The Eighteen Carat Virgin (1971)

A girl's boyfriend surprises her and they begin to have sex. The girl's stepfather walks up and watches the boy give his stepdaughter cunniligus. The boy pulls down his pants and penetrates the girl, still unaware of the stepfather's presence. He begins to hump her as she lays on her back and then the stepfather chases him off. The stepfather takes over where the boy left off, laying on top of the girl and forcing her to the ground, aggressively thrusting his penis into her open vagina.

Two young women are naked in a bedroom with a girl. They talk together about how comfortable they are to be nude around each other and then one of them undresses the girl. The girl is shown in the shower while the two women talk. The girl sits down in the tub and begins masturbating to the accompanist of her gasps and moans. One of the women walk in the bathroom nude and joins the girl in the tub. She touches and kisses the girl's body and they both begin to sexually excite each other.

The woman and girl walk out of the bathroom into the living room where the second woman takes the girl to the floor and they begin to have sex. They kiss and lick all over each other until the first woman joins them. They passionately touch each others' bodies, in a paroxysm of lust. It ends with all three females laying on their backs, exhausted from their exertions. Their splayed legs and open arms leave nothing to the imagination.

The girl from before walks into the above scene wearing a bra and panties. The woman laying on her belly introduces her in between the thrusts of the man on top of her and she sits on the first man's lap. He caresses her body and lifts her bra to expose her breasts. She stays for a while and watches the man drive his penis into the woman and then she leaves. The woman reaches out from the bed and holds the first man's penis underneath his boxers. The second man ejaculates and leaves.