When you are giving a guy a blow job and his balls keep hitting your neck like a wattle on a turkey's neck.
I can't believe he neck flapped me last night!
by Neckflap October 27, 2017
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Noun:
The sensitive part of the penis that dangles 2 millimetres just inferior too the penis head.
1. Wow, I would love a girl to blueberry my rooster neck flap
by BOOMSTICK November 4, 2014
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