how to stop being upset at someone?

Hello. My boyfriend and I have a really really really awesome loyal relationship. No cheating as ever happened, nothing like that at all! He’s amazing.

So him and his two friends have hung out w these two girls a few times, and for some reason it rubs me the wrong way. I fully trust my boyfriend! I have had guy friends in the past and he has a few girl friends... it’s not a problem at all. But i just don’t love the two girls. I told him it sorta bothers me and for some reason I just am not a fan of them..

Anyways, it’s completely a personal insecurity. My question is, how do I forget all this and stop being a little upset? It’s useless for me to care! I just can’t figure out how to be like ok who cares stop thinking about it

When we have had issues like this in the past, we are really good at communicating. I KNOW he really really loves me also. So again, this is solely a personal thing

quick edit: i don’t actually have a way to see them. my boyfriend and i are seniors in hs and have been dating since we were 13. they go to his school! which is when they hang out. i don’t go to his school.