A psychologist I met recently said to me about these things, "if you have a gut feeling that something's up, then something's up, because there's no cause to get that feeling if everything's fine in a relationship". That pretty much goes along with the general observation that if there's something to suggest it, it's there.
As terrible as that may be, approaching the OM is another matter altogether. First off, the problem isn't with him, the problem are the issues between you and your WAS for which her 'fix' is the OM. OM (and OP) are interchangeable. In fact, they needn't even be in the picture to have a WAS though it's common. OP can be anybody: if not him, then it would've been someone else, or could've been someone else. The thing about the OP is this: they're different than you, they make the WAS feel good about themselves, and it could be anybody.
Secondly, though inherently it feels right to confront him, the reality is that he could likely come down twice as hard on you. He might tell you off, stuff that can really cut you, whether it's true or not. Stuff that can haunt your vision for years to come. Why open the door to being treated to that?
Thirdly, and related to the first above mentioned, is that it takes your focus off the real issues, and knowledge of the OM can have you go down some cheeseless tunnels. He's better looking, he's wealthier, he lives in a nicer neighborhood, drives a better car, is more accomplished, knows how to captivate people at a party telling a story, a better lover, better dresser, whatever... and the truth is, while your brain gets wrapped up in that, is that none of that really matters. It really doesn't. This is all about how you love someone. So, any dwelling on the OM unconsciously influences you and thus undermines how you go about dealing with your W because of the images it paints in your head, you see?
But I'll betcha that what the OM is not is this: he's not an expert on how to love someone, how to nurture a relationship. he doesn't know any more about that than the next guy, and so, is prone to the same relationship woes as anyone else. He's also human, has his faults, and there's a reason he's not in his own upright long term relationship right now.
