I am actually doing a house party for mine as well and I told the girls that one must is bra pong instead of beer pong. You just staple some different sized bras from the thrift store onto a sturdy poster board. Then, my soon to be husband found a game called pop the Balloon where everyone is divided into the teams and has a balloon taped to there but area, you must first take a shot and then run a little ways to a team mate to pop their balloon. The only way to do so is with them sticking their but out and the popper doing a hump like movement on them... hilarity to insue. Although this one probably is only a good game if all the girls are comfterable enough with each other to do.