Throwaway because my partner is on Reddit as well -

I get home from work. Picked up groceries for dinner on the way home so when I arrive my partner and the step kids are already home. The eldest (F14) is antagonising her brother (M11) as we cook dinner, not just typical sibling ribbing but quite mean stuff. She doesn’t want to eat what we’re eating so makes her own dinner. We’re all sitting down, eating and she will not stop talking, antagonising her brother trying to get a rise from him, interrupting our conversation with stupid questions/statements, being overly loud with the dog and generally acting as if the world revolves around her as she sprawls on the couch. My partner asks what’s wrong as I’ve zoned out while I’m eating, trying to ignore the behaviour. We finish dinner and take the dog for a walk. My partner asks again, what’s wrong? I say I actually don’t want to say anything because last time I spoke about this very issue it devolved and there was no resolution aside from my partner saying “I’ll talk to her, that was two weeks ago. My partner again asked what was wrong so I just spoke - “I wanted some peace and quiet. And it’s very hard to get that when (step-daughter) is winding her brother up, constantly talking despite us trying to watch the news and generally acting like she’s deserves attention and is the most important person in the world.”

My partner said nothing. We continued to walk and I asked if they were going to say something and the response was, “I don’t know what to say.”

We continued the walk and got home. We tidied the kitchen together and the kids are upstairs. My partner went downstairs to work. We haven’t spoken to each other in 1.5 hours.