Reproduction joke. The "1+1" refers to two people having sex; the extra 1 represents a potential baby, making a total of 3 people.
"I'm gonna get laid tonight!"
"Whatever man, just remember sometimes 1+1=3."
by progamer124 January 04, 2005
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In a game of east coast darts the act of throwing one dart in each of the three different scoring regions. (East Coast Definition)
In the 8th inning Pizzy threw up the 2-1-3.
by PeterGammonsLuvChild June 22, 2005
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Pregnant.

Like one guy and one girl=one guy and one girl and one baby.
So, what happened last night?

Well: 1+1=3.
by youmeatsixfanatic February 03, 2011
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The rule of thumb for sexual intercourse , esp. in male homosexual activity , in regards to the size of the giving participants penis.
Whenever the penis is larger then 6 inches, then the receiving participants only agree to receive 1/3 of the phallus of the giving participant.

This rule dose not always apply , as some male homosexual intercourse goes by the 'breath through the pain' rule, and clarification is expected to be communicated prior to the encounter over the interwebz or in eye contact in the nanoseconds before the door closes and penetration occurs .
Kevin Smith was interviewing Malcrom Ingram, as Malcom admitted his dismay upon the idea of accepting a full nine inches of raging man meat. Kevin reminisces of his mothers 'frugality' , gets lost in a haze of 'foggy' memory, then returns to introduce to the SModcast community and the entirety of the internet the 1/3 rule.
Kev, this is for you good sir.

tarinbutler3002@yahoo.com
by eat cock-Oh we totally DO October 14, 2010
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January 3rd, 1937, the most l33t day in history EVER.
"I wish I was born on 1-3-37, so I could've been born to be l33t."
"Your mom is a 1-3-37 baby, is she l33t at sex?" (Never say the 2nd example, lol)
by David777 September 23, 2008
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demonic but simple to summon the devil at your any needs
2+1=3
by 2+1=3 March 26, 2017
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This man named jon sits here and can't Speak english. He gets very angry when you get his orders wrong. His Arm Was shot off in the vietnam War
ChOOOOSSE CHUMATOESSSSSSS!!!!!

EIGHT HASUSAGEEE!!!! THATZ ITTT!!!!

MUFFING ALSEE!!!
by Sophia Ting April 20, 2005
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