FLM24M, I felt that way when I first started thinking about it as a real possibility. Right after we had sex one night, my wife said, "I think I want more variety than just you." Seconds before she said that, I had made some embarrassing comment regarding my insecurity with my size. I had already prepared for the idea of her getting rammed in front of me, but she wanted to hook up with guys away from me -- said she didn't think she could get off with me watching. I kind of freaked out.
I think she got a little frustrated with me for freaking out because she knows I get off to the fantasy of it all. When I started considering it as a reality... that she would actually leave the house, go hook up with another guy, and then come back home to me... It definitely hurt.
After time and talking about it all, I finally communicated that I was comfortable with us opening up our relationship on her end. Eventually, she met a guy and did the deal. I was worried about myself psychologically because of how I had freaked out before (I could barely focus on work I was so distraught). However, when it came time for her to meet the guy and play, it was pretty painless.
So to answer your question, once it actually happened, I didn't feel anything but compersion (getting pleasure from your partner's pleasure). However, I know the angst you speak of, as I felt it when I realized that she needed more than me sexually.
Lastly, I wouldn't assume she loves anybody MORE than you. Even if it's not being communicated, it could well be that she loves you even more for allowing her to have subsidized sex from another man. My wife told me it made her feel more like had 'given her a gift' by allowing it all to go down.
So, hang in there fellow Cuck, and if you're worried about something, communicate it clearly to her and she should be more than happy to reaffirm how happy you make her. If she doesn't, you could have a bigger problem than whether or not you should be in a non-monogamous relationship, but I'd be willing to bet this is mostly a minor insecurity you're feeling more than anything having to do with your wife.
I don't know you, and I don't know your wife or the overall dynamic between you two, so definitely take my comment for what it is -- some stranger who hopes you're dealing with all of this as well as you possibly can.
Best of luck!
SoF
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