It is implied that the main character has had many sexual relationships outside of marriage. He has two different live-in girlfriends during the movie, and occasionally alludes to "making love" with them.
Intercourse is shown twice, but both scenes are non-explicit to meet 1970s tv standards. In the first one, the main character and his live-in girlfriend are shown kissing passionately. He pulls her shirt over her head and lowers her toward the bed. Her bare back is shown briefly. In the second, both characters are shown cuddling in bed, clearly naked but covered by the sheets. No nudity is shown either time.
Several risqué lines. The main character implies that he's been sleeping with women since he was 19.