I think it comes down to the fact that he doesn't think that enabling someone to do something that he personally thinks is wrong, is wrong. Basically his point is that it's their choice, so it's their responsibility, and he does nothing wrong by enabling them. He doesn't think that any particular behavior is right or wrong per se, which is why he has no trouble allowing cheating to happen: it's not the cheating per se that is wrong (otherwise he would feel compelled to stop it from happening), it is the choice of betraying a partner's trust that is wrong, and he does not do it, somebody else does. He *does* enable them to make that wrong choice, but he also believes that the women who end up cheating have made that choice way before meeting a man willing to be their "accomplice".
I'm just trying to understand an otherwise (seemingly, to me at least) inconsistent behavior.