He was an shy idiot from the start, i am going to dump him.
Totally agree with SM and Chima.
It was really idiotic of him to post what happened on facebook.
He sounds like kind of an idiot and if it were me I would be offended that he would think I was stupid enough to fall for such a stupid excuse and that would be the reason why I would dump him. I'm a lot smarter than that and so are you. Tell him you're not stupid and you see right through his lame attempts at lying and you're leaving. That's what I would do.
Dont get me wrong as not trying to justify anything. Men are a peculiar lot and sometimes need a wake up call to get them back on track.
I don't think 'most' men do this and am not sure where you got that information from. The guilty party?
Break up. He's a cheater who justifies it. Find a man with strong values who adores you and would never hurt you like that.
You might start of by asking him if you went to a male massage palour and the man gave you a happy ending, how would he feel and more over, ask him directly what would he do? Make him answer that question.