wife's brother

They had a pool in their backyard. One time there were a few relatives over. I was in the pool with her, her brother and two cousins( one female and a younger boy). A few others were in the backyard. Her brother was messing with my wife’s and her cousins bottoms. The younger cousin was reallllly trying to see something lol. A little later on as my wife is getting out of the pool her brother unties the strings and pulls her bikini bottoms down. Bare ass very exposed. Did look nice going up that ladder. She got up the ladder and quickly threw a towel on.