Poor M. Well, I didn't scream or yell or anything, but I was firm. Everything went into a bin and upstairs to A.'s room (it was all hers except a couple items, and T.'s item went into the trash after consultation with him). Once there, I said it all had to be put away and since there was no space to do that we had to create space by getting rid of things. We now have a full bag of stuffies, a full bag of Minnies (the snap on dress up ones and various paraphernalia), a half full bag of Doc McStuffins toys and a partially full bin with a bunch of my clothes, and a few other odds and ends that came out of A.'s room. In the course of packing up the Minnies, I found the Minnie music player that I found the book for in the playroom a few days earlier. A. and I moved from her room to the upstairs hall, and decluttered many stuffies there as well. She was a completely good sport. I didn't pressure her about anything and she got rid of a ton of stuff. The "keep" criteria seems to be: is it pink? And/or a Ty toy? There are other things she is keeping, but that accounts for a shocking amount of it. We got everything from the kitchen table put away and the room still looks much emptier than it did before, and the hall is amazingly better. M. and her dog P. departed fairly early on in this process (as we were packing up the bin to clear the table out to make space for snack).
When playdate arrived, R. got out the sewing machine, because R. (A.'s friend) and A. wanted wings attached to some of their Ty unicorns. A. and R. (husband) had gone to Michael's earlier in the week for supplies. I served coleslaw to R.'s parents (my friend D. and her husband I. also my friend of course!), and then he returned home to monitor a roast chicken and coach other child through the week's homework. D. and I had manhattans and I ate the chicken that R. had cooked on the grill before settling in to make wings. (In answer to your question, it was not wings and wings, it was drumsticks for the chicken. I know, would have been funny, right?)
Partway through our manhattans, D. brought up the topic of Halloween decorations, so I went down to the basement, pulled out that bin, and deployed the decorations. So that's done.
R. (husband) has a dehumidifier (or possibly a humidifier) filter that goes to an appliance we no longer own. Anyone got any ideas? It is NIB -- I'm thinking we may be approaching that moment where I set up a freecycle account. Ugh.
ETA: I also noticed a line of dust bunnies along the wall in the master. R. says that when he made the bed today with fresh sheets, he may have done so quite "vigorously". Dunno. I vacuumed the room, tho, because it clearly needed it. A. is having a blast with toys that she has been recently reminded of by decluttering everything else.