When you get hard and/or are being shaved by your farmer/master and get sexual feelings toward him/her. Usually happens at the point in your sheepy life at the age of adolescence. Cotton Boners are natural things and should not be ridiculed or made fun of.
"Do you see Jimmy's Cotton Boner? It's HUGE!"

"Son, Cotton Boners are natural, don't worry about it"

"Dude! Quit shaving me I think I'm getting a Cotton Boner!"

"I fuck sheep..."
by SheepsHaveBigDicks January 29, 2012
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When a dude is frantically trying to hump you but his penis is not hard.
Sue: Well,how did the hookup with that dude you met go the other night?
Wendy: Horrible. He had cotton boner but insisted we keep trying...for an hour. Pointless!
by semami4700 April 29, 2019
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