When a penis has been in contact with water for an extended period of time, whether it be bathing, swimming etc. The penis then becomes shriveled and wrinkled to the point where it is a fraction of normal size.
"Jody totally wants my d"
"What are you waiting for? Make a move!"
"I don't know I'm not really attracted to her I doubt I could even get hard."
"Don't let that stop you, just shrivel dick her!"