Hey not2,

This is a weird subject matter; it's as if you have her life all sorted out and in a neat little package. You can't do that it's her life and her body. And it sounds as though you are ok with it because it's not another guy and so you don't consider it sex or cheating and you don't consider it offensive if the woman is almost someone of your choosing (not this or that but the other is ok), if she is with someone else sexually or emotionally it is cheating.

I really think that you need to sit her down and ask her if she wants the relationship to keep going, because from the sound of things you have a completely different relationship with her than she thinks you have,

Good luck with this,

Rhian