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Thinking with your dick and not you Head. Usually leading to bad decisions and great stories to tell, if you survive.
Fred: woah she is really drunk alex maybe i should call a cab for her..
Alex(using his second brain): No its ok man she could stay at my place

Next Day
Alex: omg! my dick has spots on it
by ISPYUTOO? February 28, 2010
the penis
My second brain brought me to this video
by tory borty April 25, 2013