A California record executive named Rick Ingels picks up 2 hitchhiking young hippie chicks, worldly Carol and innocent blonde Judy and drops them off near his house and they say they'll walk around, but they decide to come to his house and hang out and he lets them in, gives them a little wine, and lets them stay. Judy is nervous and a virgin, but Carol obviously has an ulterior motive. She pretends to fall asleep on the sofa and they put a blanket over her and go upstairs to the bedroom, and Rick takes Judy's virginity.Judy is a little nervous and he doesn't push things, but it ultimately happens and he tries to be gentle.He tells her sometimes the first time can be a little rough. They go downstairs and Carol seduces him too. The girls stay overnight, and at first Rick is having a good time. Judy tells Carol it kind of felt nice but it hurt so she didn't have too good a time.The three of them go walking around the city in the afternoon, and play in the park. Then go back to Rick's house and settle in.The girls are very oversexed though. The next day at work Rick is kind of too tired to do his job well. That night when he gets home, he tells the girls he's about ready for them to leave.He'll even pay for them to get a hotel, but they don't really want to leave and keep putting it off, and delay him with more sex. When Rick finally gets tired of their endless sexual demands and messiness, and insists he has to get his life back together and they have to go, Carol shows him Judy's driver's license and it proves she's underage and they blackmail him my threatening to go to the police if he throws them out. He is forced to let them stay. Judy tells Carol they should clean up after themselves but Carol says why bother? That night,Rick locks himself in the bathroom and sits in the shower to get some peace. Judy feels kind of bad for what they're doing to Rick, but Carol is enjoying torturing him, and insists they have to keep him sexually exhausted. Rick comes downstairs, and says he's going to go to a hotel and leave them there. They imply if he does they're going to get rowdy and break things,but if he stays,they won't let him go to sleep until he gives them sex. He asked why they're doing this and Carol says they want to explore every single sexual possibility and try every single position and see what they like. He gives them a book on sex but they want to learn it first hand. Finally, Rick decides to try to exhaust them sexually. They have a 36-hour sex marathon. He tries to exhaust them and won't even let them sleep,but they don't tire.That morning he calls in sick, and ultimately he's the one who passes out. Judy wants to let him rest but Carol insists they have to keep him going. She says their plan all along was to see if they could screw a man to death! Carol ties Rick up, puts on a dildo and rapes him anally, and he screams in pain. Carol decides to get into s&m, and whips him with a belt and beats him with her fists and objects. Judy is no longer enjoying this. Carol says she's too innocent to know anything, but Judy says she knows what she likes and she likes sex, but she's realizing this isn't about learning about sex. Carol is enjoying this! Carol screams that her brother and stepfather raped her and her father pimped her out and that men claim they're all studs but look at Rick. He's clearly no stud. She beats him crying in a rage. The exhausted Rick says this is all about Carol's anger. The next morning, Judy has finally persuaded Carol that they should leave now. Rick is still alive and he's apparently not going to die. They pack up to leave, but Judy says they should at least untie Rick. They go to the bedroom and Carol sneers to Rick that they're leaving now, and he's hardly a stud. She doesn't even want him now or even to untie him because he's smelly and sweaty and dirty. He actually begs them not to go and Carol is amused, but Judy insists they better be going after they loosen his bonds.Carol and Judy get their stuff and leave the house and walk away down the street in the morning sun. Inside, the exhausted sweaty,worn-out Rick calls out faintly and breathlessly for them not to leave."I'm still alive! I need more! Don't go!" Perhaps he wants to die because they've ruined his sex life.The movie ends with a shot of the sky as the girls walk away down the street.