I'm pretty sure it's completed and an older manga, so in black and white.
It begins with two men standing before their boss ans being told they will be working together for a mission.
The top is reluctant, as he thinks the bottom is to flashy. But the bottom is very good with a gun, a kinda crazy.
The last few pages, they are doing it while standing up when some thugs break into their room. They shoot the thugs while still doing it and the bottom feels so good he leans upside down.
I can't find it anywhere, so help would be appreciated!
(づ ̄ ³ ̄)づ

I've seen the author listed as Mr. Blue as well as Pachi. I really wanna read it!