Boyfriend's Sisters Wedding...🙄

Last night she came by to ask my boyfriend (her brother) to be in the wedding. He asked me if it was okay and I said yeah it's your sister! And he then said, "well isn't she being in the wedding too?" And she said, "no only a few girls are, I'm sorry you can't". I was like uh ok (her and I are SUPER close too). 

So now my boyfriend has to walk down the aisle with her fiancées sister (again, I don't care) but the part that irks me is that, she invited her fiancée's brother and his girlfriend to be in the wedding because they're dating.. well hey hi hello I'm dating your brother and have been and we are super close so it just doesn't make sense to me. All I know is, I'm tying the knot next and she WON'T be in our wedding. Rant over.