Could you explain to me the difference between a guy who likes to get drilled up the ass by his girlfriend and a gay man who likes to get drilled up the ass by a guy?

It's equivalent to you trying to make a point of "I shoot heroin to meditate so I'm not a junky" vs junkies are people who shoot heroin to get high, it's the same difference and you could argue the person shooting heroin is very open minded, it's an excuse.

I have absolutely no problem with homosexuals, I think it's great that everyone can do what they please and be with who they please but what I do have a problem with is people who beat around the bush and make excuses, if your bf liked getting it up the ass by you, chances are he might of left you for his best friend Pablo.