Bridesmaid +1 Etiquette

I'm having a small wedding in Las Vegas in 2 months. We decided not to give single guests +1s, but we were generous to give them out when asked. I did not know that it was customary to give bridesmaids +1, so the single ones did not get one either, but no one complained. Now, I have a bridesmaid who is asking me if this guy she is dating can come. They are not a couple and she makes it very clear neither one of them wants to be serious. They have only been hanging out for a month, but a year ago they were hanging out for maybe two months until he ghosted her. Should I let him come?
Our RSVPs were due about 8 weeks ago and she never showed interest in bringing someone until three days ago. I'm also concerned because she committed to traveling/rooming with another bridesmaid. I am mostly just annoyed by how she handled the situation.