In Series 1, 2 and the Christmas special there are fairly frequent moderate sex referances. Although infrequently they are strong at times.
In one scene a character walks in on a couple having sex, they are heard moaning and the female is obviously having an orgasm. As the female character moves up towards the sheets, there is a slight referance regarding that the female has been performing oral sex/fellatio on a male character.
In one scene in the series, a strong sex referance occurs when a female character lays down and cries on a male's crotch area and the scene looks as if she is performing oral sex on him.
Some terms for sexual acts are used "dogging"
A male character hugs a female character, she then runs away in fear from the male thinking he has an erection, although it was just a baby rattle in his trouser pocket, the male later states that "She thaught i had my erected penis against her".
Some behind nudity, no rear nudity.
There are many innuendos and comic sexual terms throughout the series.
A character lays down in bed and holds/massages a womans breasts and doesn't realise he was doing it to the wrong person.
A young woman keeps asking a male character if he is "hitting on her".
Many discussions of having sex and having babys.
A character accidently puts a woman's breast fillet onto a baking tray thinking it is a chicken fillet.
A character flicks a condom into the room, the whole episode consists of that character trying to retrieve it.
A character buys some flavoured condoms for somebody, although without realising it he gives them to the wrong person.