I hate do this again, but: I'm looking for a manga

Since the last one worked so well, I'm trying again.

There's a super popular boy who flirts with just about anything that moves. He can't remember faces, only kisses? When the uke gets the wrong love letter and accidentally turns him down, the seme kisses him and makes hihm have sex before leaving (i think). Then the seme realizes he loves him but can only remember his lips. That starts a long line for kisses that makes the uke mad cause the guy can't even remember him!