When you are hittin' it from the back and you don't want to cum on her back, so you go to the fridge, grab jello, and throw it on her back.
"Hey Jackson, did you end up getting with Samantha last night?"

"Yeah, but I didn't want to finish...so...."
"No way man... did you?"
"Yep, i did the unthinkable... I Jello Back'd her."
by Ricky Man Bobby June 21, 2017
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