Frequent but brief scenes of female bare breasts and buttocks, mostly pre/post coitus.
A woman is showering. A man joins her and begins erotically touching her. She surrenders to his touch as he kisses down her body. Her breasts and buttocks are seen.
How is this an X in any category?
Two women lying together in bed topless (pressumably naked). It is only implied, no breasts are shown.
A young woman is shown in a bikini and a young man in swimtrunks.
The female protagonist wakes up in bed with a man and a woman. It's implied that they had a threesome the night before.
Young woman is shown topless and making out with her shirtless assumed stepbrother in protagonist's fantasy.
A woman catches her younger lover in bed with his supposed sister. Both appear to be naked. While the sister is shown naked (topless and side nudity), all we see of the man is his shirtless upper body and his bare legs, the rest is under the covers. Later they are shown together in bed like this in a few more scenes.
Man waiting for woman in bed, presumably naked. Only upper part of his body is shown. His sister is also present, and as a parting gesture, she seductively strokes her brother's bare back and leaves.
A young woman expresses her affection for the protagonist in a way that cannot be interpreted as anything other than lesbian interest.
Man and woman are shown sunbathing in the garden. The man is shirtless, but has pants on. The woman is wearing a one-piece swimsuit.
A woman visits a young man in his apartment. He has his shirt unbuttoned and starts seducing her. They start undressing and kissing each other, which is interrupted by the arrival of the young man's landlord.
A seductive young man is shown wearing unbuttoned shirts or partly open bathrobe revealing his smooth chest in several scenes.
A man and a woman lie in bed, she kisses his bare chest and says his name in an excited voice. It is implied that this is a post-coital scene. Both are implied to be naked. Female rear and topless nudity is briefly shown, the man's assumed nudity is obscured by bed covers over his lap.
A man rips off a woman's blouse. Topless female nudity is briefly shown. He then starts kissing her on the neck, shoulders and lips.
Man says to a woman that he always sleeps nude in seductive tone.