Long puddin' is an extension of the word puddin', quite literally. It means a long, floppy penis, of more than 7-8 inches when flaccid. It can also mean the ball sack is particularly long or droopy, but the phrase mostly refers to the penis.
"Wow! Gotta get me some of that Long puddin'!"
Kissing someone’s anus when it has a brown ring around it.
Nathan is all about puddin kissin his women!!
To take a shit into a cup, then give it to someone as a dessert. Shitcream.
She gave him a Danish Puddin Cup for dessert.
when you can't keep your hands outta your pants
Grandma says keep your hands outta your puddin patch, dammit.