Okay, so it's a pretty sure thing he schemed his way into this "meeting." Why? Who knows, I will say there are some people who really get a charge out of situations like this where there unknowing girlfriend is in the presence of this other woman.

I think I wouldn't invest more time in this relationship if this is the case. I probably wouldn't even bother confronting him because he probably wouldn't admit it anyway. I'd just freeze him out.