It's not a big shock to anyone how obsessed Izuku gets with Kacchan...
Sapphire Midnight@SapMidnight
16 views
May 05, 2025
~9 min read
1
It's not a big shock to anyone how obsessed Izuku gets with Kacchan during his heats. His alpha is handsome, strong, and smells amazing.
But people DO raise brows when the dark desire is mutual. And Kacchan can be scarily possessive during his rut.
#BKDK #BakuDeku #SpicyBkDk
But people DO raise brows when the dark desire is mutual. And Kacchan can be scarily possessive during his rut.
#BKDK #BakuDeku #SpicyBkDk
2
The first hint of his boyfriend going into Izuku's favorite way to spend his week (his boyfriend's amazing sexual prowess without a refractory period is his version of Christmas) is his scent change.
Smokey firewood gains a spicy undertone, and it makes Izuku's toes curls. "Oh."
Smokey firewood gains a spicy undertone, and it makes Izuku's toes curls. "Oh."
3
"What?" Kacchan's still half-asleep, but his body knows what it wants without needing his brain fully functional. Warm lips mouth around his scent gland, already trying to pull out the sweeter side of his mint scent.
Izuku lolls his head back, leaves his throat exposed for more.
Izuku lolls his head back, leaves his throat exposed for more.
4
The greedy mouth sucks on the sensitive skin, and the hardness pressing against the curve of his ass makes Izuku's lips part in a moan, shivering. "Ka-Kacchan, we have to...to call out of work for your-"
"Told 'em last night." Is growled out before sharp teeth nip at his gland.
"Told 'em last night." Is growled out before sharp teeth nip at his gland.
5
'He's so responsible,' he thinks, tickled pink. Kacchan always takes care of him. Pleased at picking such a good alpha to steal from the world, Izuku reaches behind him, running scarred fingers through the baby hairs on the strong nape.
"Kacchan's too good to me."
"Tch. Duh."
"Kacchan's too good to me."
"Tch. Duh."
6
But the little grunt is distracted, sweaty hands already slipping under his sleep shirt to feel over his naked hips. Izuku purrs at the fingers tracing the stretch marks on his thighs and stomach, both reminders of his growth from the scrawny boy of their middle school years.
7
"Smell so good," Kacchan murmurs, a heavy arousal weaving between his words while he explores Izuku like he's never touched him before. The sudden grip on his hips yanks him back, Izuku moaning when Kacchan ruts against him again. "Wanna knot you."
And this makes Izuku shiver.
And this makes Izuku shiver.
8
Everything about Kacchan is perfect. Izuku wouldn't change a thing about him. He's a kind partner, a patient lover, and loves to leave Izuku boneless and sated.
But when he's in a rut, he can be a little...single minded.
Mainly over wanting to knot Izuku as soon as possible.
But when he's in a rut, he can be a little...single minded.
Mainly over wanting to knot Izuku as soon as possible.
9
And Izuku loves being linked together, feeling Kacchan inside him. But the tiny drawback of his alpha wanting to knot him so quickly is... well...
Kacchan isn't tiny.
His eagerness to feel them together has accidentally hurt Izuku before, not that he minds. It's a good ache.
Kacchan isn't tiny.
His eagerness to feel them together has accidentally hurt Izuku before, not that he minds. It's a good ache.
10
Outside of rut, Kacchan gets that. Sometimes teases him about being a masochist, grinds a little harder just to see Izuku's cheeks flush.
But in rut, at the first hint of pain in his scent, Kacchan's alpha gets all upset. And it turns the fun time into visiting old demons.
But in rut, at the first hint of pain in his scent, Kacchan's alpha gets all upset. And it turns the fun time into visiting old demons.
11
It takes them years to find the best way to prep Izuku while also pleasing Kacchan's urge to be inside him.
Turning to his beautiful mate, Izuku cups his face and kisses him with a silent implication in the exchange.
He's going to give Kacchan everything he needs...eventually.
Turning to his beautiful mate, Izuku cups his face and kisses him with a silent implication in the exchange.
He's going to give Kacchan everything he needs...eventually.
12
Alphas pretend they control the dynamic, but a good relationship knows its the omega who leads.
So when Izuku puts a hand on Kacchan's hip and leans over him, lips locked against the hot mouth panting into his, his lover easily lays on his back, lets Izuku crawl onto his lap.
So when Izuku puts a hand on Kacchan's hip and leans over him, lips locked against the hot mouth panting into his, his lover easily lays on his back, lets Izuku crawl onto his lap.
13
The shedding of clothes between bites and sultry rolls of hips means that Izuku's slick is almost dripping from him with need.
But this time is for Kacchan, so he knows he's got to keep his head on straight to take care of his semi-lucid mate, who's already arching up into him.
But this time is for Kacchan, so he knows he's got to keep his head on straight to take care of his semi-lucid mate, who's already arching up into him.
14
Being a good omega, Izuku straddles the man he's loved since he was too young to even know what soulmates means.
The brush of the tip against his rim makes both moan, Izuku's hand squeezing the base to keep them both steady.
Then, like an expert, he sinks down onto Kacchan.
The brush of the tip against his rim makes both moan, Izuku's hand squeezing the base to keep them both steady.
Then, like an expert, he sinks down onto Kacchan.
15
Lashes flutter closed at the amazing sensation, and he squirms on the perch he'd live on if he could.
From how Kacchan grabs his thighs and trembles under him, maybe he feels the same.
The thrust of impatient hips under him finally pulls him back into his role of pace keeper.
From how Kacchan grabs his thighs and trembles under him, maybe he feels the same.
The thrust of impatient hips under him finally pulls him back into his role of pace keeper.
16
His hands slink over Kacchan's before sliding them off, kissing the palms that could blow his face off without a hint of fear.
After nuzzling his scent into the skin, he places them on the sheets, speaking gently to the growling alpha. "Ten minutes, Kacchan. That's your rule."
After nuzzling his scent into the skin, he places them on the sheets, speaking gently to the growling alpha. "Ten minutes, Kacchan. That's your rule."
17
"Fuck the rules." But when the hands only dig further into their crumpled blankets, Izuku sees the worried mate that put the rule in place years ago.
Purring to soothe his horny alpha's nerves, he resets his position and then puts his 'amazing thighs' to use over Kacchan.
Purring to soothe his horny alpha's nerves, he resets his position and then puts his 'amazing thighs' to use over Kacchan.
18
Though he's not the sex god Kacchan is, Izuku does everything he knows (through delicious trial and error) will make Kacchan knot grow the fastest.
The circular rotation of his hips earns deep groans from the alpha. Squeezing his inner muscles gets his first breathless swear.
The circular rotation of his hips earns deep groans from the alpha. Squeezing his inner muscles gets his first breathless swear.
19
It's flattering how quickly Kacchan gets ready to lock them together, even if that's common during an alpha's first wave of his rut.
But this is where things go a little differently than the normal omega-alpha dynamic.
Once Izuku feels the pressure, his mental timer starts.
But this is where things go a little differently than the normal omega-alpha dynamic.
Once Izuku feels the pressure, his mental timer starts.
20
Izuku stops moving, keeps his body still as the first push of the knot stretches his rim open. He moans at the pleasant sensation, his own cock drooling with his desire to sink down and take it completely.
But he keeps Kacchan just outside, which drives his rutting alpha crazy.
But he keeps Kacchan just outside, which drives his rutting alpha crazy.
21
Legs spasm under him, hands clawing at the sheets under their sweaty bodies. "F-fuck, Zuku. Lemme...fuck!"
"Ten minutes," he reminds, whining as he wiggles back and forth on the pulsing arousal inside him.
"Ten minutes," he reminds, whining as he wiggles back and forth on the pulsing arousal inside him.
22
He mourns the loss when he raises himself up, only keeping the tip in as his body clenches, needing to be filled again.
There's an embarrassing art in this game they play; keeping Kacchan on the edge, using the needy knot to slowly open him without shoving it all in at once.
There's an embarrassing art in this game they play; keeping Kacchan on the edge, using the needy knot to slowly open him without shoving it all in at once.
23
Each time he drops down, and lets wonderful pleasure fill his greedy body, Kacchan's reactions grow more desperate.
At first, it's growls and snarls, the body trained for fighting showing its power with hip shifts that nearly impale Izuku.
But he's good at riding Kacchan.
At first, it's growls and snarls, the body trained for fighting showing its power with hip shifts that nearly impale Izuku.
But he's good at riding Kacchan.
24
Knowing his mate means picking up on the tensing muscles in his stomach to prepare for the movement, and Izuku raises himself in time with the thrusts to give the alpha no relief.
He waits until Kacchan groans and settles back down, the edge waning a bit, then goes again.
He waits until Kacchan groans and settles back down, the edge waning a bit, then goes again.
25
The shift from frustration to desperation happens as he starts fitting half of the knot inside him before pulling back to raise over his throbbing arousal again.
His slick pours down from his own need, and his sweetened scent makes Kacchan change his tune into something weaker.
His slick pours down from his own need, and his sweetened scent makes Kacchan change his tune into something weaker.
26
"Please," Kacchan whines, fully losing his pride to his rut and the desire to feel the connection (emotionally and physically) with his omega. Pretty red eyes have a shine that implies the orgasm he's been denied is finally breaking his composure. "I need-omega. Need...inside."
27
It almost makes Izuku feel bad how pathetic his heart looks under him, a horny mess that loses his composure over wanting Izuku closer to him.
Because he knows it's not just because he's an omega, but HIS omega, and Kacchan's alpha instincts want to show off Izuku to the world.
Because he knows it's not just because he's an omega, but HIS omega, and Kacchan's alpha instincts want to show off Izuku to the world.
28
He slinks down, the knot almost fully in without any strain on Izuku's rim. Izuku wiggles back and forth to feel the fullness he's also teasing himself with.
The pillow under Katsuki's head is torn into with claws as Kacchan fights every urge to grab Izuku and force him down.
The pillow under Katsuki's head is torn into with claws as Kacchan fights every urge to grab Izuku and force him down.
29
Izuku forces himself to lift up once more, waits for those pretty, watery eyes to find him before he lifts his chin to expose his pale neck in a sign of submission.
"My perfect alpha." Hearing Kacchan's groan, at the praise, Izuku finally sinks down a final time. "I love you."
"My perfect alpha." Hearing Kacchan's groan, at the praise, Izuku finally sinks down a final time. "I love you."
30
Kacchan's too overwhelmed by Izuku's hips on his fully, knot popping in with ease inside, to respond with words. The hands that had been so good not touching Izuku now latch to his waist, flipping them over.
Izuku's back barely touches the sheets before he's ravished.
Izuku's back barely touches the sheets before he's ravished.
31
The intense ramming of Kacchan pounding into him spirals their orgasms up in seconds. Izuku's omega is a happy mess at how feral Kacchan looks over him, snarling and thrusting like he needs Izuku to survive.
But even with the rough treatment he'll feel all day, the kiss is soft.
But even with the rough treatment he'll feel all day, the kiss is soft.
32
When the knot fully catches and Kacchan can't move, he simply grinds harder inside, lighting Izuku's body up when his prostate gets constant pressure.
Before he can even moan out his alpha's name, he's coming, body fully accepting the bite against his scent gland with a purr.
Before he can even moan out his alpha's name, he's coming, body fully accepting the bite against his scent gland with a purr.
33
He's semi delirious over the pure bliss pulsing through his arousal. Still, he pets the sweaty nape over him as Kacchan grunts and does rabbit thrusts while his own climax fills Izuku.
Everything feels perfect, and Izuku settles in their mixed scents with a blissful sigh.
Everything feels perfect, and Izuku settles in their mixed scents with a blissful sigh.
34
A tired bump on his temple makes Izuku loll his head to the side, lets Kacchan pamper him with small kisses and nuzzles over his face.
The alpha wants to soak Izuku with his scent, as if afraid some random alpha will break into their home and steal him away. Rut brain, for sure.
The alpha wants to soak Izuku with his scent, as if afraid some random alpha will break into their home and steal him away. Rut brain, for sure.
35
But Izuku chirps and purrs into the touches, loving the quiet affection as their hips still try to rub together.
He knows they'll be having lots of sex, now that Izuku is 'stretched out' to Kacchan's alpha's liking.
"You're a damn tease," Kacchan mutters, biting his cheek.
He knows they'll be having lots of sex, now that Izuku is 'stretched out' to Kacchan's alpha's liking.
"You're a damn tease," Kacchan mutters, biting his cheek.
36
"But you like it." Izuku clenches around the firmness inside him hard enough for Kacchan to shiver. "Look, Kacchan. No pain. You did so good waiting."
"Yeah, yeah. Don't baby me." But the rumble in Kacchan's chest proves he's happy with the omega's praise. "Love you, too."
"Yeah, yeah. Don't baby me." But the rumble in Kacchan's chest proves he's happy with the omega's praise. "Love you, too."
37
Izuku hums, happy to settle into his aftercare and wait for the knot to shrink down. He knows he won't be empty for long over the next few days, if Kacchan's alpha has anything to say about it.
He really does love rut weeks, almost as much as his perfect alpha.
He really does love rut weeks, almost as much as his perfect alpha.
38
Here you go! This was from an idea I saw on @VXRIANS 's page, so thank them! I hope this was a good way to start the day.
Make sure to check in tomorrow, since I've got a new sneak peek of Dragon Born coming out. And if you haven't red it, please do!
Make sure to check in tomorrow, since I've got a new sneak peek of Dragon Born coming out. And if you haven't red it, please do!
Sapphire Midnight@SapMidnight
Wanna get away? How about with a BkDk fantasy? The new Dragon Born chapter!
Comments help keep me motivated so make sure to leave one!🧡💚 #BKDK #BakuDeku #DBAU
(Also Mob AU sneak peek later!)
Pairs: BkDk, IidaTodo, (Others)
Rating: Explicit
Chapter: 15/?
Link ⬇️
Comments help keep me motivated so make sure to leave one!🧡💚 #BKDK #BakuDeku #DBAU
(Also Mob AU sneak peek later!)
Pairs: BkDk, IidaTodo, (Others)
Rating: Explicit
Chapter: 15/?
Link ⬇️
