Seperate towels are a necessity in this house. DP is a builder and even after a thorough shower there is still grime ingrained in his skin. I make him have the cheap dark towels and I have lovely soft bath sheets.
To wind me up (apparantly in the name of comedy) he will get one of my towels and do that thing where they pull the towel back and forward between their legs. It infuriates me and makes me laugh all at the same time!