No Filter: These Actors Were Really Getting Intimate On Film!
Pink Flamingos (1972)

John Waters’ cult classic film broke many boundaries and grossed out many unsuspecting viewers at the same time. One scene in particular is notable for the purposes of this list. In it, legendary drag queen Divine gives unsimulated fellatio to her fictional son in the film.
Roger Ebert said of the film, “Pink Flamingos appeals to that part of our psyches in which we are horny teenagers at the county fair with fresh dollar bills in our pockets, and a desire to see the geek show with a bunch of buddies, so that we can brag about it at school on Monday.” His review was right on point.