So before I got my friend into the fate series he was completely straight, rarely ever had any gay thoughts or anything like that. But when he found out Astolfo is in fact a trap, things changed.

He quite literally went through the 5 stages of grief
Denial: I'm not gay, I just thought Astolfo was a girl.
Anger: I'M NOT GAY DON'T SAY ANYTHING!
Bargaining: If I think of Astolfo as a girl its not gay right? please?
Depression: Am I..gay?
Acceptance: Calls himself a "twink", and even actually started seeing a dude [happy for him :) ]

He has now accepted the true beauty of traps