Originally Posted by StillaStudent
I'm just feeling frustrated, unloved, and unsatisfying.
This is where to start. If these three things were sorted out how do you think you would look at their relationship and yours with them together? This is where the negotiating and talking begins... talk about how you feel, ask for what you need.
If you need her to not sleep on that bed with him then tell her you would feel more this way if she did and that that would not help the situation in the future. If she responds with "tough shit, I'm doing it anyway," after opening up about how you feel and telling her you are worried that you will start looking for someone else, then I would suggest that you and her are done. If she says, "oh sweety, I'm so sorry, I didn't know this was all making you feel this way," then you have a leg to stand on.
Love should be abundant, not scarce in life. Your goal is to feel like that. If you sort out the above I would be very surprised if you didn't feel just as much on top of the world as she does. If you still feel like crap and frustrated, unloved and unsatisfied, then either its over or you still have work to do. As long as she and you (and him) are willing to do the work, you will have a leg to stand on.
This is not about specific events or occurrences that make you feel as you have mentioned above, this is an over all feeling. I come to bed having had sex with Mono all the time. PN just smiles knowingly and is happy for me, rolls over and I cuddle him to sleep. It took a while to get there, but we are there and love is abundant in so many ways other than the events that happen.