The Office Party (1968)

At the Harris Company located in a nameless city in Texas, the employees are seen going through a typical day of trying to seduce each other to ease their mundane lives. The boss Mr. Marks likes to work close to his employees, especially Maxine, his private secretary, to whom he gives "a little more dictation" on his office couch. Carl, the office manager, "manages very well" with Joyce, another hot-to-trot secretary with big hair. Chuck, the averaged office boy, tries to seduce another secretary who leaves lipstick all over his face and pants. Mr. Jacobs, a shy, middle-aged field representative, is yanked into the janitor's room by another secretary who attacks him just to score with any random man, only to be caught by the effeminate janitor. Bob can't get anywhere with Janet, a cute little steno girl who can't stand him but agrees to a date anyway. Bob is ecstatic because he thinks Janet is the perfect mixture of "beauty and innocence." Janet is actually a semi-lesbian and part-time hooker who gets it on with her girlfriend before going to the movies with Bob, then does it with "customer" Carl, who happens to be Bob's roommate. By the time the titular office party rolls around, it quickly turns into an immediate orgy featuring such sights as stripping secretaries, Chuck putting on a bra, the janitor hooking up in the closet with Danny, the male switchboard operator, and Mr. Jacobs dealing with his impotence.