Glad to see this revived!
Here's some
Milly Morris videos (I need to find one more that I can't seem to find) with her lover cupping those lovelies from doggie, reverse cowgirl, others:
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A good reason you don't see it more in porn is the real fact that cupping a natural bust increases the experience. The mammary flesh is the absolute softest and free flowing on a woman's body. For myself, having my manhood engulfed in a woman's mouth or vagina when I cup her bust, control becomes a serious issue.
I've been cupping my wife's breasts for almost a decade and a half now, and it's a problem that has not been reduced -- not in the least bit -- with time. I don't cup while her mouth is engulfed around my rod or in her vagina, at least not if I want any good "sustainment." About the only time I don't restrict myself is when I'm about to blast. Of course, then it's awesome.
Goes back to the infamous dialog in
Weird Science. It can be a "waste" because it causes pre-mature ejaculation for many men, including myself. I have to limit how much cupping (or even sucking for that matter) I do when my rod is in a wet orifice.
Of course, my wife knows this, and she uses it to cause me to blast sometimes. But uncontrollably caking a pornstar's womanhood without pullout (or a very late one) or deep and hard inside of her mouth while she's going very deep is typically not very common on film. I've seen Milly with only one lover on film, so maybe they do (in an off-camera shot).