I witnessed "knocking" at a gloryhole one time and there wasn't any filming going on. I was spying a guy sucking a huge, perfect cock through a gloryhole and after watching him suck, lick and slobber all over that curved monster for a while I heard some knocking coming from the other stall and the guy sucking went down on that cock as far as he could. At first, I thought he was just seeing how much of it he could take at one time and then I thought I noticed him swallowing. Shortly thereafter, the cocksucker pulled back and I spotted some cum dribbling from his chin as he tugged on and then licked a bead of cum from the retreating cock. Maybe it was something they had worked out in advance, hard to say I guess.
If I'm sucking your cock, though, you don't need to knock. I want you to feed me your entire load, it's what I'm there for.
