He wants Yeonwoo. He's been acting stupid till now, not even recognising his own feelings. (Some of our confusion is probably due to some things lost in translation from the previous chapters).
Secondly, Keith can't have anyone else. Yeonwoo marked him during Keith's rut (when Keith subconsciously choose for Yeonwoo). Yeonwoo's Omega mark on Keith prevents Keith to pair up with anyone else.
holy shit- but-
why he acting stupid tho
His ego? Denial? I mean he said he'd never do it with a man and ended up going after Yeonwoo several times.
Plus he's very experienced sex-wise but is a noob to relationships so I guess that would explain why he acts so stupid. He doesn't know better
im confused- like confused wtf does keith want