Of course gays can pretend to be straight. For centuries in many parts of the world gays, men in particular, have been forced to act straight to avoid being jailed or executed as perverts. I think one reason that gays are so often actors is that they have been acting at being something they are not since childhood, The same thing also seem to apply to Jews: they have to learn to act Jewish when in the family and like Gentiles in schools and workplaces.
The point is that people should not be forced to pretend that they are something other than what they really are.
