When you pull out during sex and cum on someone's back without telling them so they lay down and smear semen on their sheets.
Did you hear about Drew's girlfriend dumping him? Yeah man, he gave her a mayonnaise backpack and she ruined her sheets. 1,500 thread count, bruh. That's not cheap!
by Neo-Neo Zeon July 02, 2020
(v) When hooking up with a Sandwich artist from Subway or Quizno’s or any other sandwich making establishment, and the male put his mayonnaise (jizz) into the sandwich artist’s backpack (rectum).
Sara from Subway: Hey Tina, Jake, from State Farm, came over to get a sandwich during lunch.
Tina from Subway: Oh yeah, how was that?
S: Well, he was wearing these awesome khakis so I took him in the back room and we hooked up.
T: What?! Are you on the pill?!
S: No, so I had him put the mayonnaise in the backpack.
T: Oh I love mayonnaise!
Tina from Subway: Oh yeah, how was that?
S: Well, he was wearing these awesome khakis so I took him in the back room and we hooked up.
T: What?! Are you on the pill?!
S: No, so I had him put the mayonnaise in the backpack.
T: Oh I love mayonnaise!
by HotpantsPoptarts October 17, 2016