I don't think a guy could pretend to be gay unless he's at least gay curious and would be willing to play along as far as it might go if the other guy showed an interest.
No. You fool. You're being stupidly superstitious. Are you the sort of person who stabs knives into their head thinking it will make their mind "sharp"?
What does "pretending" mean in this case. My male friends and I sometimes hit on each other as a joke, but if you're talking about physical stuff that wouldn't MAKE you gay either. However a straight man probably wouldn't do that.
What does it matter anyway?