The act of masturbating (in the bathroom).
Billy asked the teacher to go to the restroom, she asked him “Number 1, or Number “ Billy replied “Number 3.” Puzzled, she asked “What’s a Number 3?!” Billy grabbed his phone and said “It usually takes about 10 minutes.”
As a resulting of eating that bad chili, I had to go Number 3 in the toilet all day.
Number 3 is a term for ejaculation
Man 1:Sorry i had to go to the bathroom
Man 2:Number 1 or number 2?
Man 1:Number 3
Named for the third thing men do in the bathroom, masturbation.
"Make sure you go for a number 3 before your date Dave, you should never leave the house with a loaded weapon"
Noun, can be used as a verb in some situations.
Masturbation. Similar usage to a Number 1, or a Number 2.
"You caught me taking a number 3"
"I've gotta go number 3, brb"