The league getting used to having Shouto around the hideout bc he's always there for Dabi...
The sort of casual "that's Dabi's boytoy" where they know Shouto will keep his mouth shut because if he does, he gets to have a place where he can sit in Dabi's lap and get his hole stuffed
The day Shouto slips up and moans "Touya-nii" while Dabi kisses his neck in front of the entire league is pure utter chaos and they never hear the end of it
"You're not just fucking a UA high student, you're fucking your BROTHER" said in the same tone you would use to roast your friend. Bc that's what they're doing.
But once it's out ohhhh all bets are off. Shouto and Dabi are downright SHAMELESS after that while at the league hideout. Shouto comes over and straddles his lap in front of everyone and starts complaining about their dad while he's kissing his neck and leaving hickies there
Moans Touya-nii and Nii-san bc he knows it makes Dabi harder and makes him cum faster.
I have more but I have to stop before I start talking about piss kink