when you get a boner in the morning, and you dont know why, its just standing tall and strong!
by tittyT December 1, 2002
A boner that occurs when someone wakes up in the morning usually because the body is automatically holding in urine.
Ugghh, dude. i needed to take a piss but i had a serious morning boner and had to bend over!
by Alex \m/ January 31, 2007
MBMP, MBMPing or Morning Boner Mangina Pissing is the only alternative to attempting to piss with morning boner and subsequently pissing all over the walls and floor of your bathroom. It is a simple technique, unconventional, but highly effective, wherein you stand with your ass facing the toilet, take your four fingers with your thumb extended upwards at a 90 degree angle, and fold your dick back between your legs as if to create a mangina.

Then, bending over and looking between your legs at the toilet behind you to ensure you do not miss the bowl, you proceed to piss, firmly holding your morning boner in place to prevent it from springing up and wreaking havoc.

Using this technique will allow you to avoid pissing in the shower or having to painfull force your boner downwards
Example #1:

Steve (to Bill): I can't stay over at my girlfriend's house anymore man
Bill: why not?
Steve: her mom caught me morning boner mangina pissing last time and now thinks I'm some sort of queer.
Bill: she obviously doens't know anything about dealing with a rock solid, red hot morning boner.
Steve and Bill: (yelling together) Morning Boner Mangina Pissing!
by shiteater9000 April 14, 2010