What is Love Stains?
1.
What Neill Ptrick Harris left in the back of Harold's car in Harold and Kumar go to White Castle.
"He're's $20 for the burgers, and 200 for the car. I left some, ah, love stains in the back seat, you'll see."
2.
When a guy gets cum all over a piece of furniture.
"Hey man, thank's for letting me borrow your car last night! Oh...here's 50 bucks."
"....uh...what's the 50 for? You're my bro, it's free" he says, giving back the $50.
"You'll find out in a second, thanks again!"
"...OK..."
he goes back to his car.
"WTF!?! He cummed all over the bitch in the front seat!?! Awwwwwww hell naw! $50 won't cover these love stains!!!"
See
3.
What you leave in the back of your friends car after you borrow it for a date with your girlfriend.
John,"Here is $20 for your car."
Greg,"My car! What did you do to it?"
John,"I left some Love Stains in the backseat."