Devils three sum 

When the ratio of man to woman is 2:1 in a three sum. Hence the two horns on a devils head symbolizing well.. yeah.
Devil's three sum has rules mind you. 1- Never look the other guy in the eyes. 2- By no means may you ever cross swords. 3- Keep high fives to a minimum. 4- Make sure if and when one devil goes backdoor, its the last move..noone wants to share an Oh Henry bar.

Me n' my best buddy hooked up with this wild chick who wasn't satisfied with simply dinner for two so we took her back to the my place and danced the devils three sum all over her.
Job well done.

Devils three sum by Lemski January 15, 2009

Three Summon

When two incredibly hot women invite you to have a threesome with them.

Bob was three summoned by the chick with the big titties and the girl with the phat ass.

Three Summon by crazyJMV February 26, 2010

threesum

Having sexual intercourse with 2 people at the same time

Last night i had a threesum with these to chicks

threesum by Raynersdfgcvb June 13, 2006

Threesum

Sexual intercourse between three people, usually hotter when three girls.

After hanging up on a Skype call, a threesum is usually what partakes as a nighttime activity

Threesum by iMindfreak October 30, 2011

Threesum

Sexual Intercourse involving a male and 2 women.

intercourse involving 2 males and 1 women is a train.

The crowd began to advance upon the Threesum, and Omally was in the vanguard. By then the Threesum was already past its prime.

Threesum by catniporangejuice March 22, 2022

National threesum day 

Day when a girl gets tagged teamed by two males

National threesum day is the hottest

National threesum day by ChronikGodz April 11, 2019

Shall I compare thee to a summer's day? 

your hot.

Boy: Shall I compare thee to a summer's day?
Girl: What?
Boy: Your hot.
Girl: Oh ok.

Shall I compare thee to a summer's day? by vllyhottie94 May 15, 2009