An act in which three partners (2 girls 1 guy) engage in a sexual activity. In said activity the guy has sexual intercourse (vaginal or anal) with girl A proceeding to ejaculate inside of her. Girl A then proceeds to stand over girl B (whilst girl B opens up either her vagina or anus) and girl A release the "wiffleball" into girl B.
Brian- Dude, I hooked up Susan and Naomi last night.
A slang term for a penis. This was invented by many rappers/hip-hop artists throughout music history. It is usually used in the context "beat her with a wiffleball bat." or other variants such as "brought my wiffleball bat."