When your titties are as hard as knuckles.
Man, he has a case of titty knuckles.
by John_Wick May 1, 2018
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A large mountain like nipple. Often pointy and longer then 5 inches
Bro, did you see Jenessa's tittie knuckle and that party last night?

-- Yeah bro shit was pointy!!
by Tottyknuckelbro May 27, 2017
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