There’s multiple definitions for this one icl-

It’s an inflatable thing outside your house at Christmas which you pump up

Or we could be referring to the act of actually blowing up fatass with some kind of bomb..
“Man I really wish I could blow Santa
“WTF WHY WOULD YOU WANT TO BLOW UP SANTA?!?!”
No I meant give him a blowjob idiot”
by Imverysmart:) September 30, 2023
Get the Blow up Santa mug.