It's called acting.

Interesting article here about how kissing another man is sometimes--more often than it should be--seen as the bravest thing an actor can do.

Excerpts:

Judging from their interviews over the years, actors who have filmed scenes in which they have pointed a revolver at someone's head and pulled the trigger still think gay kissing is the grossest thing they've ever had to do for a movie.

Women actors who've kissed other women in love scenes, meanwhile, sound like an enlightened other species in interviews about kissing. For them, it's no big whoop. The men, on the other hand, talk as if they've outdone themselves and are now ready to accept their golden statue.