A sexual maneuver whereby a male inserts or "mashes" his soft penis into a woman's vagina. The penis then becomes erect, leading to the term "baked potato." This term comes from the song "Do You Love Me?" by The Contours. In the song, they sing "I can mash potato." Originally an arcane dance form, this term has taken on new meanings in the bedroom. This term was coined in a Minneapolis basement by three men playing ping pong.
Steve: You give her the mashed potato?
Mike: Nah, man. I was already hard.
Steve: Yeah, it's a difficult move. The only way to really do it is if it's the seventh time for sex that day.