As the moment continued Dabi was very visibly nervous now, but Keigo just kept getting closer. 

"I u..uh yeah..." Was all that Dabi could speak in the moment.

Keigo had finally gotten close enough to let Dabi see his true height and the winged hero was much, much shorter than the villain

 They then started to argue teasingly because Dabi kept calling the hero short or tiny. Yet,soon Keigo became very off guard while Dabi was still very flustered and nervous while Keigo showed obvious signs that he was comfortable around him now.

"I can uhm tell you're more used to people getting attached to you than i am." Dabi said

"Not, really ...that's..uh front." Keigo responded.

"We both know you have fan-girls." Dabi said teasingly

"I'm not really all that interested by them..., they never really ruffled my feathers the way you always do...Now we're this close and I never knew I'd ever be held by you.." It was obvious Keigo spoke from the heart.

"I couldn't let you be alone on your birthday...I honestly thought you'd have a girl over or be at some huge party or something..." The villain responded 

"I'm not really as sociable as everyone thinks,....ya know..? I'm more of a vibe to some good RnB music and drink some good wine alone..." The hero says as he sighs

"Sounds nice...Hey, sorry if the cake's gross by the way.." Dabi laughs awkwardly 

Keigo laughs, "It's alright!" 

The winged man was just hugging onto Dabi because he was convinced at this point the Dabi didn't want to really kiss him, but he was surprised when Dabi grabbed his face and kissed him deeply out of nowhere. 

Keigo when he kissed Dabi back started out sloppy but smoothed out as they kept kissing and his heartbeat now really started to speed up.