I have a question about etiquette that's more out of curiosity than anything. I have a good friend (she's actually going to be my MOH) who is single and has been for a while. When she goes to weddings and has a plus one, she brings kind of random guests. Not like guys she's dating casually or whatever, but friends. She's talking about bringing her younger sister to my wedding. We are going to a mutual friend's wedding next Saturday and she is bringing her female friend from grad school. She invited me to get cousin's wedding once. It's almost always female friends who she is not romantically involved with at all. She also usually knows lots of other guests at the wedding she is attending. Other than being kind of odd, is this okay to do?