His friends hate me!!

[Guest]

I have been dating this guy for about six months now and we are great together!! I am older than he is - I am 30 and he is 25 - and in the beggining this was an issue for me - however I have gotten over it. Because of this issue I put off meeting his friends, until about a month ago when I decided to bite the bullet and meet two of his friends - an engaged couple. The evening was a distaster!! I should probably tell you that he was previously involved with the girl in this equation - and when i say previously involved i mean they slept together a couple of times a few years ago. (Her fiance is his best friend and is completely unaware) Well I was nervous about the evening and while it started out ok it quickly spiralled downwards. The other guy was very nice and really tried to make me feel comfortable - but the girl was another story. She invited another couple over that evening and she and the other girl spent all night playing cards and talking - ignoring me outright!! I came to the conclusion that she has feelings for my bf (obvious right?) and that the only reason she is with her guy is because he makes a lot of money - i mean it was the first time i met them and she was demeaning him and calling him names right in front of me. The evening was a horrible blow to my self esteem - which i have always had problems with anyways. So besides all of that my problem is this - on saturday - two days from now - i am attending a wedding with my bf at which she will also be in attendance. I went out and bought a new, hot dress which makes me feel great but in the back of my mind im freaking out. I mean not only will she be there but i have to spend the reception seated at a table with her and her man. I haven't met any more of his friends (I have been too afraid to) but they are all a very tight knit group of which she is the ringleader. I want to go but Im honestly thinking about bailing. Any advice? Please help!