Definitions by Eddie fun

Zipthuding 

The sounds created when a zipper is unzipped and a large cock is displayed and subsequently drops to the floor, sending reverberating sounds through the immediate area.

Donnie was so proud of himself he began to strut around the office, unzipped his pants and his huge member fell to the floor making a huge zipthuding sound.

Zipthuding by Eddie fun August 14, 2019