You probably made an ass of yourself the last time you were drunk, but as long as you didn't rub your ass on any expensive artwork there's someone out there who's more mortified than you are. Yesterday 36-year-old Carmen Tisch was charged with felony criminal mischief for punching, scratching, and sliding her butt against a painting worth $30 million. Police suspect that Tisch was drunk when she assaulted "1957-J no.2" by Clyfford Still in a Denver museum devoted to the late artist, causing $10,000 worth of damage. A spokeswoman for the D.A.'s office says, "You have to wonder where her friends were," and that's an important message: Friends don't let friends go on a drunken rampage in an art gallery.