Friends butting in?!

Nicole
The other day I posted about my boyfriend going out with a group of friends. Girls were there it's fine he told me I wasn't worried. I trust him completely. One girl was there with her long time boyfriend and I know her. Both my best friends are upset and saying that he shouldn't of gone and why wasn't I invited. One friend told me not to be nieve and that "are u kidding me". One friend has been bitter since her break up a year ago and the other is married and probably following the bitter one. They saw pics online with girls in them which my boyfriend is no where near them. I don't think I should be worried. What does everyone else think?!