Just don't discuss it and walk away when she does.

mrsconn23

Dear Prudence, 

I tried to be kind to my stepsister and it blew up in my face. She got engaged and I offered to cater her engagement party. I bought all of the food, only for her to break up with the guy three days before the party.

I ended up donating a lot of the food but a lot went to waste and I was out several hundred dollars. My stepsister didn’t give a crap and worse, when she got back together with the guy she expected to continue the catering gig. I told her no and to consider my first attempt to be the gift. She got pissed off and started to badmouth me to everyone in town. I got tired of it and told our family that I wasn’t going to the wedding even if there was even going to be one (which I doubt). I have been avoiding family events if I know she is going to be there but that isn’t going to be possible forever. Any tips about how to deal with her? She is like a dog with a bone when it comes to grudges.

—Backfire

banana468

"Everyone I'm still out $700 plus my own sweat equity for the party that didn't happen.  She can bad mouth me all she wants but she hasn't given me a dime." 

VarunaTT

I wonder what LW's family is saying.  If I had a family member like stepsister, who then bad mouthed other sister, I'd shut her down so hard.  I think if I were LW, I'd make sure that everyone knew what had happened from my end and that for now I'm not attending if she is there.  When I do go, if stepsister continues to have the audacity, I'd shut her down again and walk away from her, over and over.

mrsconn23

I just don't know how stepsister going all over town talking shit works.  Like, no one asks a single follow-up question?  It would take about 2 of them for the stepsister's story to fall apart. 

Also, I think LW may be slightly sanitizing their (justified, based on what's presented) reaction.  They could have been an asshole (again totally understandable) and it was more of a 'fight' than they're letting on than just a simple 'no'.