"A form of mutual masturbation then begins, with the foreskin or foreskins rolling back and forth over each penis, or with penises thrusting against each other inside the foreskin. For men with very stretched and commodious foreskins, the goal is to engulf as much of the other man’s penis as possible."
But wait.. there's more..
"As might be expected, docking is thought to be practiced more frequently among men who are homosexual or bisexual; however, there seem to be a considerable number of straight men who have docked with another man."
See
@Oldschool and
@picholas , you too are doing like a metaphoric online docking by going back and forth on this source thread. But dont worry, as I told my mom when she caught me doing this with my priest, it's not gay, a lot of straight guys do it.