Top definition
This is when you are Having sex with a girl with a prosthetic leg or arm. You take it off and wear it as a helmet while you keep fucking her.
She didn't have a problem with me pulling a Unicorn helmet while fucking her last night. I must say i felt like a is a mythological creature in bed!
by BigBGank March 02, 2010
Get the mug
Get a Unicorn Helmet mug for your bunkmate Georges.