I agree with LR (happening alot these days.) My fiance is Completely mono. When I came out I told him MY truth and hoped that he could love and accept me as such. I didn't ask him to find a girlfriend or to try to be poly. I asked him to love me for me. It's a huge thing to ask of him, but I wasn't asking him to change who he is deep down inside. I asked him to accept who I am deep down inside. But, this is my story not a generalization.
I think with any partnership in life, someone has to make a sacrifice sometimes to keep the partnership in tact. It's up to the people in each individual relationship who is capable of making what sacrifices. Be it, my favorite play and his favorite game playing same night same time. Who will sacrifice if we want to spend the night together? To, I'm poly, you're mono, who makes the sacrifice so we can be together? I don't think the sacrifices matter much as long as the person making them is truly capable and willing to make it and still be healthy and happy for the long haul. I know in my relationship I have sacrificed my "fair share" of things. Some at the time I was more than willing to make and others I really was upset about, but we survived and we are both happy with the outcome.
I'm sure there are poly people out there who have stuffed it away. I don't think you'll find them on this msg board.
And Also, I think a monos who love polys support group would be grand. Like minded people giving advice on pros and cons of this relationship. A true understanding of what you're going through. It sounds way better than, myeah of course you'd say that, you're poly. LOL In all seriousness though, it warms my heart to think of my fiance having s group of people that get what he's feeling. But thats not really the support group you were talking of. Sorry for getting off topic.