"Y'know, this is SO much better for a rec room than a ping-pong table!"
They say all things come to him who waits, and although I rarely have the patience for that particular strategy, sometimes it DOES work out! Way back in July 2008 I posted a vidcap very similar the one seen above (it had a dot covering her pubic hair, back before I realized that Google considered breasts and vaginas to be pretty much the same thing, as far as Adwords is concerned.)
Aaaaanyway, I posted it because it looked very much like a vidcap to a movie, a curiously mainstream looking movie. CURIOUSLY mainstream because the clothing and decor looked very early 70s/late 60s, but there was a naked woman tied up in the middle of the picture. It was full frontal nudity, and THAT you did not see in mainstream films in those days. But the setting and the actors looked like something from a TV comedy series of the time.
Well, a day or two ago an anonymous poster came up with the answer: it's from Below the Belt a "roughie" from 1971. "Roughies" were films in which women were treated violently, as the softcore porn makers who made porn for drive-ins and smokers realized that they were not going to be able to compete with hardcore porn and so forth, so they went with violence along with the sex, a move that didn't work at all, but did lead to the production of a bunch of moves that were bad in every respect.
A vidcap from "Below the Belt" -- same scene, different cap. Same movie, alrighty!
(See IMDB listing here.) Apparently Below the Belt has been released by Something Weird video as part of a double movie set along with something called "The Godson," you can get it here. Back then I speculated that it might be from a roughie, well, I got it right! Hey, even a stopped clock is right twice a day -- if you wait long enough.
Thanks, anonymous poster!