I went to a wedding of one of my female friends. We are a group of a dozen friends from college, all were invited.
She had a lot of sisters none of us knew before the wedding. And she had a really gorgeous ass!
When she introduced our group to one of her sisters one of my other female friends noticed the sister had the same fantastic butt shape as our friend.
So we started the game "tell who's a sister of the bride by looking at her ass" - and we were really successfull!
When the bride noticed she enjoyed all the attention for her butt. The whole group commented on her ass and made her compliments. Two female friends were even brave enough to grope her a bit