His perspective - update

I’d like to thank all those who have commented that can relate to my story!

While watching my wife with another man, I feel both jealous and turned on. What surprised me was how deep the two feelings were intertwined. I never imagined jealousy could be a turn-on, and if you haven't experienced that, my words will probably just sound confusing or farfetched. Before I'd seen my wife with another man, if someone had told me he was turned on by being jealous, I would have said that ‘your crazy’.
What happened was this. My wife cheated on me. It wasn't a longterm affair. When she was done, she confessed to me, and was deeply sorry. I felt all the things a husband usually feels in such situations. I was furious. I cried. I felt betrayed. But, somewhere in my mind I realized I was actually turned on. At the time, I had way too much anxiety and anger to focus on that.
Luckily, my wife and I have a really strong relationship. When this happened, we'd already been together for many years, and I didn't for a second think she wanted to leave me. I certainly didn't want to leave her. Over the next few months, I found myself feeling less and less angry and upset. After a while the anger was completely gone, and I was left only with the turned on feelings and thoughts, which was now impossible for me to ignore.
I started fantasizing about watching my wife with this other man. I told her this, and it became part of our pillow talk. I asked her to describe her experience at great detail, and it took about four times for her to be able to get through telling me without me ejaculating after she said, "then he kissed me"… It was very, very strange to discover that, at a relatively late age, I'd learned of my fetish. And such a counterintuitive one. A few google searches (for "cuckold") proved I was far from alone.
If you've never experienced it, the best way I can describe it is by comparing it to the adrenaline rush many people get from horror movies and roller-coasters. Why would anyone purposefully go to a movie or amusement park to be scared? Isn't being scared a bad thing? Apparently not, for many people, if the fear is in exactly the right dose. Few people want to be chased by an actual axe murderer, and most people get bored by lame, not-scary horror films. To be satisfying, a horror movie must flirt with danger without getting too intense.
The same was true with my cuckolding experiences. I found that if my wife just had mechanical sex with another guy, I got bored. I learned she had to be really into it, making love to the other guy rather than just fucking him. It has to be intimate and she has to be really into it (or him) -- or it wouldn't make me jealous and hit the mark.
So I am just like a horror-movie fan who wanted to be scared but not too scared. I get turned on when my wife simply holds hands with another man, while being held in his arms or sitting on his lap, kissing him deeply. My stomach will start to turn over with jealousy. Not to mention the feeling of watching as she looks into his eyes and smiles as he first enters her during each encounter. She has the most beautiful smiles!
She can get me nauseous and the good kind of butterflies in the stomach all at the same time. Very confusing, but also very intoxicating!
Have I ever said, I feel so humbled and lucky to be married to my wife. I love her with all my heart!