Clay's on a roll - kind of

So Clay refuses to roll over. He has done it a few times (although we have only witnessed it once). He is a happy baby, and is happy just about anywhere, back or stomach. He doesn't roll over, but he sits up for a long time mostly on his own. Sometimes I put the boppy behind him, but he does really well alone. Tonight Brandon sat him up in the bath and he thought that was pretty cool. Whenever B tried to lay him back down he flipped out until he sat him up again.