An erection caused by someone you're not supposed to be attracted in the first place, eg, teachers, cousins, hot aunty, your best friend's mom or your best friend.
'Dammit, your second cousin is freaking hot.'
'i know, she gives me forbidden boner all the time'
When a guy gets hard just from light physical contact with or just being around a person that he is crushing on. It happens without warning and can sometimes create an awkward situation if the other person notices.
Jimmy: Hey Daniel! Me and Jessica are having an arm wrestling contest. Do you want in?
Daniel: Nah, with Jessica there I'll just get another Accidental Boner.
Jimmy: Jessica is pretty hot. I understand.
A game that takes traditional leap frog to another level.
How to play:
Minimum of 2 players, and all players must be male.
The players must take turns leaping over each other whilst completely naked, and avoid becoming sexually aroused.
The last man without an erection is declared the winner, also known as the "Last Man Not Standing".
When a girl is so hot that you spend most of your sexual thoughts focused on her, leading to a massive erection that seems to almost never go away, she has given you the eternal boner.
Guy 1: "Dude, I can't stop thinking about Anna. She's so hot, bro."
Guy 2: "That's because she gives you the eternal boner, man."
Guy 1: "Word."
A disapproval boner is what old, judgmental people get when they see something sexualized that was produced for the consumption of a younger audience. Clearly a sign of intense self-loathing.
As defined by Jon Stewart on the Daily Show 5/1/14, referencing Bill O'Reilly's condemnation of Beyonce's sexualized videos.
"Bill O'Reilly probably ran that sexyBeyonce B-roll in order to bring some much-needed disapproval boners to his aging audience."