My reading of the post above yours, in the context of the conversation it appears in, is that you cannot overcome your instincts so there's no point in even trying to rein them in. If it just means to say we don't live up to our ideals all the time, well, OK, that's true, but I don't see where it's going.
Actually you have to make a number of conscious decisions to have an affair. "It just happened" is an excuse.