A 14 year old at wearing a bikini at a pool party isn't going to have much to look forward to when shes 18. Her mother is totally foolish and stupid to allow her daughter to wear something like that. The hostess has every right to speak quietly to the mother and offer the daughter a long Tshirt.
A very long t-shirt.
If its refused its within her rights to ask them to leave. You wouldn't allow anyone to do in your home what you wouldn't allow your own children to do. This should have been done as soon as it was apparent that the swim suit would not meet approved community standards.
You know the more I think about this, the angrier I get, you have a very young girl, encouraged to expose her body to get attention...just how stupid can that girls mother get?
EDIT
The mom let her buy the bikini in the first place, unless you are going to tell me the girl drove to the mall, the mom allowed her to wear it to a coed party, she could have saved it for working on her tan around her own pool in private. Lets just get this straight a fourteen year old girl should not have her azz hanging out for boys to gawk at. NO, its the totally wrong message to send to the other girls at the party, and very confusing for young boys to be able to deal with her advertising something that hopefully isn't for sale yet.
The fact that another less attractive girl wasn't the object of jealousy isn't the point, she was just as wrong and the same over sized T shirt should have been offered to her. To wear over the offending bikini.
The pretty girl in the bikini is going to spend quite a few years with rumors dogging her and shes going to be labeled easy with all the grief that entails. I don't expect a girl to understand, but a mom should, the girls mom failed her badly by not understanding that making a group of girls angry and jealous is misery waiting to happen. I feel sorry for the young girl.