leaves of three, let them be 

A common saying used to warn others of poison ivy. Poison ivy typically grows in stems with 3 leaves to a plant.

“Watch out man, those the leaves of three, let them be. Don’t ever touch em”

leaves of three, let them be by dubzallday May 6, 2021

cut it in three 

the act of fucking a sandwich to completion

“i got so horny while eating my sandwich today, i had to cut it in three”

cut it in three by dracshaft December 25, 2022

Give me three 

It originated from shooting three-pointers in basketball and wishing for it to go in or chanted as a celebration after scoring a three-pointer. Very similar to just shouting "three" or "get in". It can also be used in contexts where desirable things are in sight and the achievement of aforementioned things must be celebrated.
Similar hype words include lfg, we take those.
Hand gestures indicating you have just shot a three-pointer must be accompanied by saying this phrase.

"Hey John, these presale opportunities are available for a bargain!"
"Wow, you're right. Give me three (gesture as if just shot a three-pointer)"

Give me three by sandole July 30, 2023

one thousand three hundred and thirty seven

See 1337.

one thousand three hundred and thirty seven by WordMaster July 28, 2003

Three's company 

Old sitcom starring JOHN RITTER.

Come and knock on our door.

We've been waiting for you.

There's a lovely space that needs your face,

Three's Company, Too!

Three's company by larstait October 14, 2003

Less Than Three 

Less than three = <3 = "heart" used commonly on MySpace

< is the mathmatical symbol for "less than"
3 is the number

"I less than three you"
is the same as
"I <3 U"

Less Than Three by Miss_1221_Murder March 26, 2007

three fingered salute 

to press press CTRL ALT and DELETE on your PC thus resetting it .. derived from the 3 fingers you use to press the buttons.

John:"Damn my computer has froze!!"
Dave:"Give it a three fingered salute!"
John:"But ill lose all my work..."

three fingered salute by Evil-Ernie June 2, 2003