My OH lives with me and his 2 kids stay with us a few times a week.
My OH pays maintenance for the kids but his ex only works part time and money is tighter for her so a lot of the kids clothes are hand me downs. There is nothing wrong with this, having an older sister means most of my clothes were hand me downs as I grew up.
I have a pretty well paid job and earn more than my OH, I'm not rolling in it but I have more disposable income than my OH and his ex. We've had issues with the ex sending the kids with clothes that they don't like and refuse to wear or are on the small side, so I buy them clothes to wear when they are at ours. Nothing expensive, but just nice clothes that they like. My OH and I have also bought clothes for the kids and given them to the ex for the kids at hers.
AIBU to not want to the kids to wear the clothes I've bought for them to wear at ours, when they go home? My OHs ex isn't very organised and we wouldn't get the clothes back.