A belt dick is the part of the belt that sticks out after it is fastened around ones waist. It is often because the belt is too short to reach the beltloop, therefore, you end up with a belt dick hard on.
omg she must have gained ten pounds over the weekend. her belt is too short and now she has a belt dick hard on. usually accompanied by slight to severe muffin top
Like the more notable, strap on, the dick on a belt allows a person without a penis to engage in pleasuring their partner(s) with a large, hard, cylindrical object.
The dick on a belt can refer to a homemade strap on as well, which is constructed of your everyday dildo/vibrator, a belt & perhaps some duct tape.
A black choker necklace identifies individuals who love to suck dicks and are probably professionals at it. Therefore they have a black belt (around the neck) in sucking dick