Imagine Krbk in their third year.
Both are in the locker room, changing their school uniform to their hero costume because they have to go to their agencies, you know, Kirishima with FatGum and Bakugou with Endeavor.
When Kirishima finishes changing he turns

to Bakugou, smiling, and the blonde knows exactly what he wants.

"Give me a kiss"

"I don't wanna"

"C'mon!" Kirishima says with a pout "A good luck kiss!" He insists, closing the gap between them but a hand in Kirishima's mouth stop the action.

"Don't be a baby, when you come back I'll give you a welcome home kiss. Now go"

Who was gonna to tell Bakugou that this would be his last chance to kiss his boyfriend. Now all Bakugou has left is to wait in the hospital bed for Kirishima to wake up.

"Perhaps, " he thought " if I had given him the good luck kiss..."