Dear Prudence,
My brother “John” married “Kim” last year. She is a perfectly nice woman, but we don’t have much in common and aren’t close. At the wedding, her mother got catastrophically drunk, sexually harassed the best man, and then got into a fight with the best man’s wife (a bridesmaid). The next morning, when the best man quietly moved tables so he wouldn’t have to sit with her, she screamed at him for “shaming” her and tried to stab him with a fork. No one on the bride’s side blinked an eye. The rest of us assumed they were just trying to salvage the rest of the day by keeping the peace, but when my brother asked Kim about it later, she said the best man shouldn’t have “flirted” with her mom and then “acted coy” afterward just because his wife found out. That’s … not what happened. We all saw her mother get out of control in front of everyone.
John said to let it go because weddings can get emotional. But then the same thing sort of happened at Christmas when Kim invited us all to their house for a party. This time, her mother tried to set fire to my mother’s dress, supposedly for flirting with her boyfriend. Kim said that it was my mother’s fault for being too friendly and that her mother had been cheated on a lot. John said that Kim knew her mother was in the wrong but was just really defensive of her. Now Kim has invited everyone to a birthday barbecue for my brother next month. We don’t want to go, but we also don’t want to skip my brother’s party. Every family has a difficult member (we have an uncle who gets drunk and angry if you won’t let him drive), but Kim’s mother actually tries to hurt people, both drunk and sober. How can we handle this? Not go? Go and do something if Kim’s mother gets upset again? (I wanted to call the police at Christmas, but Mom is worried that will alienate Kim and John. His best friend, the best man at the wedding, has already stopped talking to him because of the wedding day incident, which actually probably could have qualified as sexual assault if he’d wanted to push it, never mind his wife’s black eye.)
—Family Freakout