You have to tell them to do that, otherwise they'll just wander around the tub

This is what happens when I don't follow the wisdom of Bill Cosby:

Apparently I wasn't very clear tonight. I brought the kids upstairs for showers, turned on the water, told Matt to get undressed and get in, and then I went into my room to turn on a show for Jillian. When I came back to the bathroom, there was Matt, in the tub, as I asked him, the water running, looking all pleased with himself. One problem, he took off all of his clothes - except his undershirt. I said, "did you forget something?" And he looked at me completely baffled. "Your tee-shirt Matt?" He looked down, all shocked, apparently he didn't feel the soaking wet undershirt against his skin. That's my son.