I would ask her to get out, wait 10-15 mins for me to finish ... Depending on when she walked in and then remind her to knock on the door. That would suck .... My dad walked in on me once. He was supposed to be in Vegas for work. Left me alone with the house for the weekend .... Needless to say I invited this smoking hot chick over. We drank a little and I had her bent over the couch when he decided to come home. Lol it was awkward ... He turned around and left just needed to get his folders for work. She stayed the weekend. 0_o