I think Liam was attacking those who say he's gay by saying he looks for females, and Harry was addressing the fact that there wasn't a need to bring that up.
I feel like the group are kinda sick of each other though.
I know it's inevitable this sorta thread would pop up, but why do we insist on exclaiming and labeling everyone's sexuality when most of us don't want the same for ourselves? He hasn't outwardly said he's gay, so clearly he doesn't want everyone to know if he is or isn't.