Seriously OP. Don't over analyze the situation. I had a similar situation the ONE time I actually got my wife to go to a nude beach. I love running around naked. My avatar pretty much says it all. The wife is just not into.
However, we were sitting enjoying the sun. While there was not some young stud dangling bait in front of her, It was obvious that she was checking the competition out. There were some that definitely had a larger flaccid than me.
Rather than get mad, I just smirked and in fair play, checked out some really nice racks. That serious exception to the rule came bopping along the beach. She spotted him in the distance and followed him (with her eyes) ALL the way down the beach. Her head was bobbing up and down with each step he took, in sync, with his kickstand bobbing. I glanced at him, Had to admit, he was semi-erect, judging from the distance we were at, He had to be nine inches minimum and maybe 5 ft 4in tall. That just made it more pronounced. Otherwise, I was staring at her with that bemused look on my face that says "What the hell women?". She finally looks back at me, "WHAT?"
Like I said, rather than get mad, I took it in stride. She married me. She went home with me. WE had awesome sex. She was quite happy with me. She could have been fantasizing about him, but it didn't matter. The actual event was with ME.
Relax dude. Women look. Women fantasize. Women wonder about big penises just like men do about huge boobs. I often wonder what I would look like with huge boobs. Sorry. mind strayed for a moment.
She married YOU. She went home with YOU. Relax.
I did jokingly ask her later, "So what would you do with something that big anyway?". All she said was, "Nothing. NO THANK YOU.......... but, I would like to hold it just see if it is real..... " LOL. I found it all very amusing.