Re (from UpsideDown, Post #1
"Am I being utterly unfair in this? Does this make me a terrible person?"
It's not terrible to feel the emotions, and it's not terrible to express the emotions. The big question is, what will you do about these feelings? If you actully insisted that he have less outside contact than you're allowed to have, then that would be an inequity.
I would continue with the introspection, and with brainstorming for ideas of things that might make his outside romances easier to choke down. Would it help to get to very well know the person he's seeing? Ideas like that. Any idea you can think of.
I'm sure you and he will have to work out some compromises. Cross each bridge when you come to it, but give thoughts to the potential bridges just in case.