The point of these questions is that you probably have considerable ability to differentiate truth from fiction. You can hone those skills with additional techniques you can find on the 'net. IOW, you can figure out what's true and what's not.
I used to believe that. In fact, I thought I was pretty darn good at it. But I was so blindsided by the A, and that was a real "you suck at this" moment, that I still, years later, have difficulty trusting my intuition anywhere, with her, work, friends.. It's a moderate problem for me, because I don't trust myself anymore, and, for my work, I need to trust myself, I have to speak with authority and make decisions, and, even today, I feel like I'm not as good at it as I used to be.
And really, does the quality of your W's A sex make a difference, or do you just fear it makes a difference? (Real question.)
I think she'd say "it makes no difference" (even if the OM was 1000X better than me). It's just not what she was after/wanted and it's never been that important to me. But, to me, it does make a difference; the thought that the best sex of her life was with OM is just.. Well, it's impossible to digest. Talk about a boner killer!
Come to think of it, if she changed her approach to sex in response to your saying why you want something, you may have a winner ... and however good A sex was, you've probably made M sex better for her.
I'm going to tell you something kind of funny. I always wade into these arguments because I feel like I live this situation, I am the guy who's wife went pornstar (not the only one, but one of those who's trying to R and posts a lot) with the AP and denied it from me in our marriage. But, what you said above.. I'm nearly sure it's true. I think our sex is better. I don't think the OM rocked her world and she's still pining for it. I really don't think any of that anymore. But I do fear it! Kind of like how some people are irrationally afraid of planes, driving to the airport is more dangerous and yet, some people are terrified of plane travel. And the reason is obvious, getting on a plane that's going to crash is perhaps one of the worst ways to die that many of us can fathom. You're afraid of it because, if it's true, it would be impossibly awful. I concede, and I'm pretty sure I'm right, this is, at least for me/us, now an irrational fear (I don't think it was an irrational fear right after the A though, she gave him so much more "access" that I just didn't even have a chance to compete. Imagine if a woman has "sex" with 2 men, one man she gets naked and lets him go down on her, the other man, she gives him a handjob.. Which was better for her? Well, physically, I'm going with the first guy, but it doesn't mean the 2nd guy sucked, he just didn't have a chance to show her he was good.. That's kind of how I felt right after D-day). It's a rational fear because it can/does happen, I'm sure of that. But it's irrational because, in my case, I'm pretty sure that's not what actually happened in her A. Our sex now is fantastic, it really is, and I think it's greatly eclipsed what she got/had with the OM.. Think, but I do not (and cannot) know..
And how can you ignore your experience that it takes time to build variety and great quality into sex. (I apologize if you've told us how long your W's A was; I missed it.)
Actually, that's not my experience, and I think it's a BIG part of the problem for me. I've had "porn star" one night stands or very casual relationships. In fact, I've had more of them than I've had "porn star girlfriends". It didn't take "time to build great quality into sex", in fact, if anything, that was the enemy in many of my previous relationships. Novelty was a huge turn on for me; I honestly can't remember when my first time having sex with someone wasn't a "wow". It may have happened, but something would have had to really have been "off" (not attracted to her at all, or, more likely, way too much to drink). I think that's a big part of the problem honestly, because for me, new sex = great sex. I do realize and believe, particularly female posters, who say it's not that way for them at all. In fact, I kind of laugh/cry to myself and think back to those I've had sex with before and think "Yeah, that was a wow for me, and she was probably counting the minutes until it was over". Sad, but almost undoubtedly true.
As to the "why him and not me" question, what sort of answer has she proffered?
She didn't care what he thought of her (if he thought she was a sl*t, for example, for doing some specific acts). And she did care what I thought of her. That's probably the most cognizant answer I've gotten that does kind of make sense. It also points to "need more therapy, stat!" because, while somewhat understandable as a reason, it's also so f**ked it's a little hard to wrap my head around.
It. Is. Not. Always. About. Penis. Size.
No, it's not. But I think this is just a common male, or perhaps just my, insecurity. We see people talking about it all the time, and, while intellectually I know it's not the end all be all of sex, it still bothers me. It's irrational, I know. Honestly, again, probably TMI, but if I wanted to worry about something "more real" I'd wonder more if he has a golden tongue than a 10" penis, my wife (and most women, in my experience) enjoys that a lot more than being blasted with something that can double as a baseball bat should you leave your at home on the way to the ballpark.