Need unbiased opinions

Here’s the scenario..

Someone has been in a relationship with a man for 3 1/2 years. Today is his birthday. She asks him if he invited his females friends (she knows who these women are) to his get together tonight and he says yes. She then asks why didn’t she get an invite and his answer is that there’s some guys he graduated with that will be there that he hasn’t seen in a while, and he doesn’t want everyone in his business.He also said that if it was just his friends that she already met, that he would have no problem with her being there. She obviously is suspicious at this point. How should she take this?

Their relationship has been rocky from the beginning.