Originally Posted by Monoconfused
But that is never at the cost of their relationship.
I agree with TP on this point. This alone would give me pause, it sounds like she is placing you secondary to her boyfriend, and that is wrong.
She's trying to balance a developing relationship but at the cost of an existing one. You say they are not being wholly unfeeling but they ARE; she is sacrificing your feelings and her exisiting relationship for a new one. It's all part of New Relationship Energy, she's swept up in new feelings and the fun of a new relationship, and she is ignoring your needs. If it is one sided as it seems then there's only hurt for you in it; if she is not willing to see that she will need to sacrifice some of her new relationship for you, it's not going to end well.
I mentioned before that when TP started dating Mr. A we set fairly strict rules for her time spent together; this was to prevent a situation like you have because TP would have disappeared in a NRE puff without them and I'd have been left hurt and alone.
One concept that TP and I embraced at the start of her relationship with Mr. A was "Fair but not equal." essentially acknowledging that I had been here, had put the effort into the relationship and because I was the one being asked to adjust and be ok with the new relationship I had a more important role and feelings to consider; but that also meant that Mr A had rights (for lack of a better term) to be treated fairly in this relationship.