There is male buttock nudity in one episode (locker room of the football team). Sex is not directly shown, but discussed between characters.
In one episode, we see two characters kissing, the girl points down and you see the man go down out of frame before the scene ends. Oral is implied but nothing is shown.
There also are mild sexual references.
Several pictures of scantily dressed women (one of which is topless) are visible in a man's locker. Lasso puts tape over the sensitive area.
At one point, several sketches of a woman's breasts are shown.
In season 2, a woman masturbates. Her lower half is covered by bedsheets but it's very obvious what is happening.
Ted accidentally walks onto the field with his pants unzipped. No nudity.
Jamie answers the door without pants on and we see his buttocks as he walks back to his bedroom.
It's implied Ted slept with Sassy.
Roy threatens to flick Jamie's genitals (he answered the door wearing only a t-shirt).
One episode's plotline involves nude photos being leaked we see a clip of Keeley presumably nude leaned over a chair talking seductively.
Beard is seen wearing thong style briefs in the final episode.
There is an episode where two women are shown kissing.