ExP only recently has a place DC can go and stay, ages 8 and 3. The first time they went I thought it would make sense to send them both with a bag of basic clothes, couple of pairs of pyjamas and underwear. I explained to ExP I'd done this and said keep those bits, wash them when worn then you've got plenty for the weekends they stay.
When they came back the bag came back with all the dirty clothes they'd worn, plus all the clean spares I'd sent which hadn't been worn.
So AIBU to expect him to be in charge or clothes and washing for them while they are at his, rather than me be his washer woman plus having to keep packing them a bag and unpacking each time?