Special Order (1974)

Comely, but ditsy and underage diner waitress Karla gets paid by a sleazy customer to have sex with him in an office building. Karla enjoys the experience so much that she goes on to have additional carnal encounters with a biker, two truckers inside a trailer, and a janitor in an elevator. Karla walks in on businessman Mr. Stevens having a torrid tryst with secretary Barbara, so she joins the couple for a threesome.