Is a general term given to a non life threating symptom that usually occurs as a result of spontaneous intercourse, whereby the male has engaged in intercourse through an open jeans or trouser zipper, causing localised trauma to the penis shaft.
Can also be caused by running Commando for extended periods in tighter fitting attire.
A more innocent form of Zip-rash may sometimes occur directly under a persons chin - as a result of wearing an incorrectly zippered up Cardigan, Jacket or similar.
"who could I turn to.....? my doctor ?? c'mon I only had zip-rash...!!!"
Q:"Good lord... you had blood in your undies........?."
A:"All OK...it's just zip-rash"
"We did it on the dancefloor again... ummm man - i got zip-rash, so i gotta sit down now"
"Guess I didn't wear undies for a week and now i darn got zip-rash again"
Redwood through an open zip may inflict a more painfull and severe zip-rash, thus requiring medical attention.