It's funny because... 

A phrase which is said after a joke by an individual who hears it.

The element within the joke that makes it funny, one that someone normally figures out for his/herself, is made obvious by being verbally described by the individual.

Saying this phrase leads to mixed results. Some may be annoyed by it and feel that it ruins the joke. Others may find it humorous because the element is somewhat funny in itself.

John: The early bird gets the worm, but the second mouse gets the cheese.
Friends: <laughter>
Fred: It's funny because... the mousetrap kills the first one.
Friends: <sighing, shaking heads>
---
Dave: A guy goes to his doctor for a checkup and the doctor tells him that he needs to stop masturbating.
"Why's that, doctor?" the guy asks."
"Because I've gotta finish this exam."
Friends: <laughter>
Craig: It's funny because... he's masturbating in front of the doctor.
Friends: <chuckles>

It's funny because... by YouAndMeInJapan December 11, 2011

It's funny because it's poisonous! 

something you say to explain why you're laughing after someone just ate a food item that you gave them (that you slipped arsenic or something into).

"HAHAHAHAHA!!! SUCKA!!!"
"What's so funny, dumbass? I'm just eating this pizza."
"It's funny because it's poisonous! I just slipped a shitload of cyanide into that pizza."
"OH SHIT!!! I'm gonna kill you motherfu-" (drops dead)

It's funny because it's poisonous! by Nick D March 6, 2003

It's funny because it's poisonous! 

When your tripping real shrooms and some guy you dont like is tripping the bad kind of shrooms.

I hope your not laughing because this is my 1st time tripping shrooms.
No bitch it's funny because its poisonous.

It's funny because it's poisonous! by Matt Fox February 28, 2005

It's funny because it's true 

Statement of truth used when something non-fictional, ironic and hilarious occurs.

<GhettoChubb> Me and my sister went down to the supermarket, and this huge fat chick was standing near the frozen-food section, and I swear to God I thought it was my sister, and I slapped the bitch on the shoulder and said 'Losing a little wait?' and the women turned around and kicked me inside a fridge. A closed fridge!
<Hymenia> Hahahh, its funny because it's true.

It's funny because it's true by bastardized bottomburp May 17, 2003

It's funny because it's poisonous! 

Something you say when a really freaky person does something funny.

Rohan: Hey, Scott, stop touching my ass!
Evan: It's funny because it's poisonous!

It's funny because it's poisonous! by Anonymous February 21, 2003

It's funny because you are adopted 

something that someone says when a adopted kid makes a lame ass joke like this:

Adopted Kid:your mom just had a baby and yo dad too!

COol Guy: it's funny because you are adopted

Adopted Kid:no it's not

Cool GUy: yes it is motherfucken adopted gedezez! *blasts adopted kids brains out*
Cool GUy: yo uare adopted!

Adopted Kid: lick my gina machine

Cool GUy: it's funny because you are adopted haha im gonna shoot you now!!!!!!!!!!!!!!!!!!!1

It's funny because you are adopted by JesusChristfootball October 12, 2011