Some help please. It's a yaoi manga and a one shot (more like, a part of series of one sho...

Some help please. It's a yaoi manga and a one shot (more like, a part of series of one shots? Does that even sound right?), if I am not mistaken. One of them delivers something to the other one, then that deliveryman rapes his client. Turns out, they were just doing some sort of an act because the one who acted as a client wants to do it.