Report him to the teacher. He’s spreading lies about you and making you and your child out to be a target for the other kids in the class. (Seriously – even if he truly believed you were a hoarder, the kids do not need to know that!)
Do not engage. He wants attention. Don’t let him add fuel to the fire – don’t allow him in your house.
The guys name is Mortimer? Lol. I got a good chuckle from that…i don’t know why.
Next time just say Mortimer either shutup or ask your wife to buy you a proper house so you can stop pretending you don’t need stuff that you actually want….loser.
Ask other parents and kids over for a playdate, particularly the parents who know a lot of people.
Once you have other people who can defend you from this odd notion then it’s a non-issue.
Someone was telling me their family referred to breakfast cereal as “kibble” and they ended up having to explain to a concerned teacher that they weren’t feeding dog food to their children!
INFO: did you choose Ermintrude as a name because you are a Terry Pratchett fan?
Op, don’t bother dealing with Mortimer. Talk to the school directly about the inappropriateness of his gossiping.
I would suggest that given he’s been talking and yes bad mouthing you to your daughter that despite how much you want your daughter to remain friends with his, you can’t allow her to be under his supervision anymore. Yes that means no more play dates or sleepovers where she stays at his house.
What he’s doing could be considered parental alienation given he’s been trying to get your daughter to dislike you.
On top of which, Mortimer has started spreading rumours about your house to other parents, and their children have started saying it your daughter. That’s some level of proto bullying.
Talk to the school, and no more play dates or sleepovers where Mortimer is alone with your daughter. He can’t be trusted not to continue his weird ass campaign of harassment.