When you're showering with a girl and she's giving you a blowjob, you shampoo your hair and rinse the bubbles on to her hair. She then uses those bubbles to wash her hair, all the while still sucking the dick. This is called a Head & Shoulders.
I just got a Head & Shoulders last night. I've never felt so dirty and clean at the same time.
When you are being masturbated by a partner, and said parter shoves a travel sized bottle of head and shoulders up your ass. Typically done in the backseat of a car in the middle of the day.
Guy 1: Man, Laura invited me to a Head & Shoulders Party last weekend. It was awesome! We had it right in front oh her church!
Guy 2: Ew.
When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).