Lot: This biblical figure was the original bad dad, and doubled up George Washington by being the grandfather of TWO nations. After Lot drunkenly slept with each of his daughters, their offspring became the patriarchs of Moab and Ammon. This is the earliest and creepiest example of "two chicks at the same time."
When celebrating Father's Day, be glad you weren't sired by one of these men. Some of them were absentee dads, and the rest should have been. And if your dad actually is listed here ... we're so, so sorry.