Several references and suggested sex. Partial female nudity only (naturally) in the sex scenes. No full frontal nudity of females or males is actually shown, as focus is on the upper body and facial expressions.
In the first season, sex and nudity occurs, but is limited. S 2 is worse.
Season one:
A few scenes take place at a club, where women wear short shorts. Two women are topless with pasties covering their nipples.
A man hangs up a poster of a woman, and it turns out to be the mother of another man in the gang, her breasts are clearly seen on a paper posted to a wall and shown over and over again for considerable amount if time. The man later has sex with the woman, when she rips open her top, you can very briefly see her breasts from the side up close.
A man working at an immigration office, has slept with 67 immigrant women, some of them underage. A character finds disturbing pictures taken of the worker and the underage girls, the women are in underwear only, no shirts, one completely topless. However the pictures are never shown up close. Photos are briefly shown several times throughout different episodes as the show progresses, sometimes up close.
Young women go streaking. They are seen at a distance. When three of them run on camera, they are shown from behind revealing their backsides, which is uncomfortably awkward as the 2 men gawking at them are 50s/60s while the females are minor school girls.
A man and a woman start kissing, sex is implied.
There are a few strange sexual references, like about male midwives getting erections while delivering babies etc.
Season two:
In the first episode a man and a woman implied sex / undressing. No nudity.
A man has thoughts about another man that we see played out, it shows two men lovingly touching and kissing.
A man and woman engage in sexual banter a few times, he also spanks her but it is humorous.
A young man and a woman with newborns start kissing passionately, the man starts kissing her breasts, the woman implies he sucked milk from her breasts and she finds that disturbing, he denies it. (no nudity)
A young man with a fetish smells a womans bra in a locker room where he works, parts of this are shown several times, he is shown grinding on the lockers, the last time it is shown, he is shown 'masturbating' from behind. (no nudity)
A gay mafia boss has an Asian housekeeper, implied that he wants a relationship with him. In one episode implied penis touching (very briefly distant shot looks like you see a penis.)
A man and a woman start kissing and later have sex, which is not actually shown. But afterwards they are shown together; the man clothed in a tshirt and underwear, the woman completely naked. Her buttocks are shown nearly the entire scene and her breasts are shown several times as they talk and as she moves around. No male nudity whatsoever is shown.
A few scenes take place at a dancing club, (women with pasties covering their nipples), one man has a lap dance during which the stripper's silicone enhanced breasts are flashed twice. No male nudity.