Catfish, I feel similar emotions as you do when my girlfriend is with her other boyfriend. The way that I'd like to solve it is by being told many details, even if the details would make him seem like he is a superior lover. I want the chance to own my own feelings. I also rather try to get turned-on by my partner being with her boyfriend rather than just stay neutral about it. I need to try to turn it into candy in order to feel compersion. I'm questioning this perspective, but only because she is not telling me as much as I'd like. If she were telling me more, I don't think that I'd be questioning my perspective.
The woman that I'm dating has told me some details, but not to the extent that I desire.