LadyFunkenstein said:I don't know whether this was covered already, but a man who grips his cock too snugly when he masturbates is dang near impossible to make cum from oral alone. I have seen it at least ten times now: they use the kung-fu death grip on their penis, and you simply can't match that with your moutn. I've asked men I have suspected with this problem to jerk off for me, and sure enough, there it is, the too-tight grip.
I'm inclined to believe there is some truth to this. If a guy regularly masturbates aggressively, especially if he doesn't use lube, it's hard for a mouth to match that level of stimulation. Oddly, it never gets more difficult to achieve an orgasm through vaginal intercouse. Wank-fu may be strong, but Pussy-fu is stronger yet.