I'm mad at my significant other for going to dinner with my friends
Why are you so upset about her going to dinner with your friends?
I want to go to dinner with my friends. She's been spending all her time with them and I'm pretty sick and tired of it.
Even though it might upset you it is wrong to try to be controlling of your significant other. You should trust your significant other and let them do as they please.
Wtf, why can't I be a jealous boyfriend if I want to?
Maybe you should say you want to join them, they are your friends too. I would not act jealous about it, it m ight make you look bad.