I don't watch much TV and have never see coupling, but I'm gonna take a guess.
The Brits are always making fun of our prudery in not showing nudity on TV.
Perhaps, since we can't turn shows on for a little nudity, we actually demand some semblance of entertainment value? (I know it's a stretch, considering our own TV isn't very entertaining, but since Monty Python and Fawlty Towers stopped I have never seen an entertaining British show.)
Shalom.
There's implied nudity on the BBC's "Coupling" but I haven't seen more skin on the characters than you would see at a public beach (Well, in one episode, Jeff shows enough that he would be wearing a thong on said beach).
Give the BBC series a try, it's pretty funny.
BTTT for BBC "Coupling" fans.