Mr fuckboy is a common term that can be used to refer to a person who likes to go around messing with girls with, no real intention of keeping a loyal, long term relationship unless friends with benefits is one. It can be used as a code name so, it's easier to talk about someone and not get caught in the act. It can also be used as a simple joke.
"Oh hey, look it's Mr fuckboy!"
"You need to stop acting like Mr fuckboy"
"We need to talk about Mr fuckboy"
"You need to stop acting like Mr fuckboy"
"We need to talk about Mr fuckboy"
by I'm weird af October 15, 2017