If you're the owner of a karate studio, like Derek is, then it's pretty much martial arts law that you have to reveal your baby's gender using your impressive karate skills. Derek's wife Theresa was ready with the camera as Derek side-kicked a board in half to learn they were having a boy!
There are less athletic ways to learn your baby's gender, though. You could always just plan a family game night! Pilar Freeman and her husband gathered the family for a round of hangman, where they learned they were having another baby girl, who's coming just in time since their eldest daughter just went off to college.