May I also add a comment on kids and what they might say? Kids are factual in my view, not deliberately mean (at primary age at least). My kids have gone to places and said ‘your house is smaller than ours’. They’ve also gone and said ‘you have nicer food’, you have better toys, your TV is on all the time (the holy grail of awesomeness to my kids) and ‘your mum is way nicer than mine’. All wonderfully honest (to them) assessments of how they see the facts.
Their own friends do the same: your house is bigger/smaller than ours, my room is bigger than yours (my eldest’s is tiny), I don’t like your mum’s cooking, I love your trampoline etc etc. The good and bad all fall out of their mouths without thinking.
They don’t mean to be rude. When kids say things like that here I say gently ‘in this house we don’t say we don’t like dinner, we eat what we can and politely leave the rest’ and so forth. I’d hope my kids friends parents do the same.
If my kids say ‘charlie’s House is tiny Mum!’ when they come home from charlie’s then we have a chat about how we should probably keep those thoughts in our heads outside our own home, in case we hurt peoples feelings. They understand this quite early if you explain it and make it logical rather than tell them off.
It’s education for life, gently teaching our kids that people are different and it really doesn’t matter, but we need to take into account how our behaviour or words can potentially hurt others.