Cruise for Swinging Couples (1980)

Glenda becomes obsessed with the idea of having Larry sexually. Glenda attacks what she knows is Heaven’s chink in her armor. She gets Heaven into bed with Irene and her, and arranges for Larry to come and witness the scene. Irene, however, is the one who takes Larry to bed. So it shouldn’t be a total loss, Glenda brings Heaven to witness the scene. Heaven is completely disoriented and she begins to take men to bed without discrimination. Then Glenda takes Larry to bed. When Heaven is scheduled to leave by boat, Glenda and Irene give her a sendoff party that finds Larry in bed with the three girls. For the first time Larry has intercourse with Heaven. When Heaven leaves the bed to make her boat, Glenda and Irene are thunderstruck. Larry leaves with her for her trip across the sea.

Now he and those he recruits on his quest for answers must dig through old memories and eager assholes to find the answers they seek!