This is a sexual activity where a male buys a Shamrock Shake from McDonalds, which is basically a McFlurry which is defined by McTwist and the Shamrock Shake being a neon green color is defined by the Neon in the title. Then the male puts his penis inside of the Shamrock Shake for as long as he likes and then slowly pulls it out leaving neon Shamrock Shake residue on his penis. He then performs intercourse until the girl screams because she is bleeding. The color of blood, red, is the Stoplight color telling you to stop.

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed