I only have a ton of snipets I remember-
It's about a rich 18-year oldish looking guy with his butler, who's the same age. The butler's really emotionless and stuff, and one day the young master decides to tell him to get a new haircut(which is his own), I'm pretty sure one of them has two beauty marks on their face. Also, they end up having sex with a girl who apparently doesn't mind anal. At the end the young master's dad abandons him and his butler saves him but with an implied 'sex slave' thing.
I'm pretty sure it's not the main story of the manga, and just one of the later one shots.
Thanks for any help in advance.

It sounds like "Yubisaki Kara..." (Chapter 5) of Devil x Devil by Sawauchi Sachiyo.

THANK YOU SO MUCH Yes this is it I was having a fit because I couldn't remember it bless your soul!

Heh. You're welcome!