Milkshake Marine 

A man who drinks protein milkshakes way more than he actually works out, to build what looks like strong muscles, but is actually the work of milkshakes. This gives them the illusion that they are tough ....however the reality is very different.

Person 1 - man look over there at that tough looking guy, his pecs are huge! he must bench press for a day job!
Person 2 - nah he's a milkshake marine, he lifts more shakes than he does weights...

See : Douchebag, Show Pony.

Milkshake Marine by HIV69 November 14, 2012

Marine Corp Milkshake 

A sexual act in which Marines partake

ritualistically. Multiple men initiate sexual intercourse with a female and, one at a time, bust inside of her. The last one to blow his load in her must drink the rest of it out of her vagina.

Damn, it looks like Devin’s gonna have to drink the Marine Corp Milkshake!

Marine Corp Milkshake by Oonga Boonga August 2, 2020