AITA for not cleaning up after my roommate?

I feel like this is common sense but this argument has been going on for over a year. It’s time to come to Reddit. I (25F) have 2 roommates. My best friend Josh (24M) and his little sister Jen (15F). The dishes are a shared chore between me and Jen. we have no dishwasher! But we have made it clear to Josh that we are not washing dishes that he doesn’t preclean. (Definition of preclean: rinse it out and put it in the sink directly or shortly after using, NOT after the food dries/burns/hardens/adheres) Me and Jen agreed to wash his nasty dishes one more time about a month ago but we stated that was the last time. There is now a pile of dishes we’ve ignored because he couldn’t be bothered to clean up after himself. These dishes include cookware with burnt on food. Mind you, he said he’s washing them tonight. But he made sure to mention that it’s our job and we should do it. In response, remind him that we’ll only do it if he rinses/wipes out the damn things! Like bro, yes we’re the dishwashers but we ain’t ya momma. I shouldn’t even have to ask this, but AITA?