I second nycindie. I've seen things go very bad when couples try to require an "us only" relationship. That flies in the face of reality. When there are three people, there will be three relationships...A and B, B and C, A and C. You will at some time find yourself without the third person. If you have no way to relate to each other individually...well, that's not a good way to approach relationships....
Hang in there and do what you need to do for yourself. You have to be your own advocate here.
"But you've got to be tough when consumed by desire
'Cause it's not enough just to stand outside the fire
Life is not tried, it is merely survived
When you're standing outside the fire"
Garth Brooks and Jenny Yates