That film was called Hot Times, or A Hard Time For Archie. (link here)
This is basically a mainstream porno film that tried to tout itself as "American Graffiti...with sex!"
The main character (Archie) is a black haired Jewish kid with an afro, his friends name is Mughead, and he tries to sleep withe Bette and Veronica.
You know. JUST like the comics.
What's really funny is that this movie is available to watch, unedited, on youtube. That's right! You can watch seventies twenty-somethings pretend to be teenagers having sex!
As a teenager I was able to rent this movie from my local video store, no questions asked. And I rented it a few times. Many a few times. For a teen boy pre-internet living in the prairies this was absolute gold for destroying my vision.
The times I wasn't able to rent it I knew that my buddy had rented it, and it was an unspoken piece of information between us, a shameful thing when I would go to the place on the rack where the VHS box stuffed with styrofoam stood and see that it had been rented, or vice versa.
This movie is awful, and even the memories of it are pretty bad. As a teen I realized that the dialogue was stilted, the film production was super low, the sound quality was atrocious, and had I been of the inclination to voice my opinion of the film at that time I'm sure it would have been a scathing indictment of the genre.
But...there was boobies. There are a few movies that are live action versions of the Riverdale Gang, like Return to Riverdale. But this one film really appealed to my teen appetites.