Joel was playing along. What with the laughing, wagging his little finger around, spanking Aaron with pillows and other various objects, staying in the room, etc, he didn't demonstrate that he was actually uncomfortable. And that + the rest of the housemates all laughing and egging it on made the whole atmosphere seem like messy, drunken banter. Being naked in front of people is inappropriate, which is why they should've just warned him or called him into the DR a while ago before they actually did, but the fact that they just told him to stop and let him go back into the room shows they didn't initially deem anything as "sexual assault" or anything of that nature.
Joel knew exactly what he was doing with that "personal space" "fourfiveseconds from throwing hands" speech. I don't use.
