What is Semi-boner?
1.
When ones penis is no longer erect, possibly either after blowing ones load, or just losing an erection. A semi-boner is often used for playfully slapping ones friends in the face while they sleep for a hilariously good time.
To try and piss my friend off, I got a semi-boner and helicoptered it around in his face.
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2.
A
Some guys get a semi-boner to playfuly slap each other in the face with it.
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