I agree with GG and nycindie. I too am in a triad, and right now the focus is on the three of us and my wife and our third. The relationship with our third and I is close but not as intimate as I would like. I have had to adjust to the wife and third being in the throes of NRE. I learned early on that relationships in triads have to be nurtured and allowed to grow at their own pace. Sounds a bit like your BF and GF are experiencing NRE and acted out with it. I know the fear of being left out or left alone...I struggle with it often. Just keep trying to communicate and express what your wants and needs are. Sometimes there will have to be a compromise. Just be sure to be as clear as possible with each other and be willing to renegotiate things periodically. Negotiation is another crucial piece of the triad, in my opinion.
Best of luck!