look up any word, like spook:
 
1.
When two penis heads touch together.
This most commonly happens during a threesome via an act called "double penetration" when two males accidentally pull out at the same time and knock the tips of their penises together. "Hey bro, I didn't mean to turtle knock you last night, It was a total accident."
by Joeislegend05 November 13, 2010