Dangerous passions

9pm, BBC1

Kelly is a slim, long-haired, not-unattractive young woman. Walking into a pub in well-cut jeans and a white vest-top, she could no doubt turn a few male heads.

But if they knew what she is really like, those men would run a mile. Because Kelly is "probably the most jealous woman in Britain".

She makes her boyfriend's life a misery - constantly accusing him of looking at other women and having furious rows in which she beats him up. They have been banned from almost every pub in town because of her rages.

She even refuses to let him watch Baywatch or Big Brother on TV because he might fancy some of the women involved. (All right, Baywatch is fair enough, if you are a bit mad - but banning Big Brother??? Surely some mistake.)

Kelly's story is told in this interesting, but overlong, documentary, the first in a series about the extreme side of human emotions, starting with jealousy.

There is also Val, who at 61 admits she is behaving like a teenager by stalking her ex-boyfriend to check whether he is seeing a new woman. Plus Alan, who took a knife to his wife's lover, and Gordon, who felt jealous and betrayed by his wife.

Mind you, he had good reason - it turned out that the two children he thought he'd fathered, weren't his. A much more understandable reason to be upset than any of daft Kelly's imagined slights.

In fact, you may spend much of this programme wondering why Kelly's boyfriend, Nick stays with her. Why doesn't he just cut and run? But be patient. When Kelly has counselling and begins to deal with her jealousy, an intriguing (and not totally admirable) explanation for Nick's loyalty emerges...