An activity to which the person (usually
male) proceeds to
force a a 5 cent coin down their urethra (dick
hole) then wanks and cums with the coin still lodged in there, the challenge is complete when the person has successfully climaxed and then also pulls the coin out.
John: I'm gonna do the 5 cent challenge tonight,
wanna do it with me?
Bob: no fucken
way cunt, that's fucked
John: it's your loss it's actually quite pleasurable
Bob: whatever you say