When someone farts on or near your balls/vagina and the resulting movement of air tickles your balls / vagina.
" Yeah it was crazy. I was big spoon,she was little spoon and passed out. And I was falling asleep but then she fart tickled me and I couldn't help but be aroused. Is that weird?"
"Right in the middle of the lapdance she fartickled me! so I took the $20 out of her c-string and stormed out."
Portmanteau of fart and tickle.
The fact of pressing your lips on somebody's stomach (usually a baby) and blow on it. The result is a tickling sensation and a flatuation sound.
In that way, it is a kind of raspberry, but for the sole purpose of tickling and not contemptful in any way.
Stop being moody or I'll have to fartickle you.