Straight and lesbian romantic and sexual relations play substantial roles in the story lines. A gay man makes mildly lustful comments and observations. In Season 3, his relationships play a role; men are shown kissing men.
Making out occurs regularly; we see breasts fondled (over bras only) a few times, and many episodes show kissing and cuddling in bed leading up to sex that is mainly implied. Sex is only seen very briefly a few times, typically with one person totally under the covers and without exaggerated movement.
The only nudity in the first two seasons is a split-second view of a woman's breast when she flashes a man. Women are seen in bras occasionally, in panties less often; male nudity is never seen.
An extramarital affair decades ago is key to an on-going story line. Sexual coercion by powerful people is key in one episode.
In one scene, a woman and man are walking by a river at night. The woman takes off her dress and runs away playfully before the man catches and covers her up. Female frontal nudity is shown.
A man and a woman are shown talking laying in bed. The woman's breast is shown for some seconds.