These requirements must be satisfied:
1. Two men are in a room together and they are naked.
2. They both like each other enough to penetrate the other.
3. They are both gay.
4. One man (the bitch of the two) is taking it up the ass. (by "it" I mean the other man's penis, and by "up the ass" I mean up the ass.
5. The man who is ramming his rim-rod up and around his partner's sphincter must then use one hand to "Reach-Around" and masturbate his partner until he cums.
6. It can be done with two girls as well but then it's not as funny. Oh and they don't necessarily have to have penises.
Harry Potter was fucking Ron Weasley's asshole nice and hard when Ron asked him for a reach-around, shortly after this, Ron's penis was spewing out a geyser of gayness.
One time Hermoine asked Ron for a reach-around, however, Ron informed her that she didn't have a penis.