Not that I didn't see this coming but if this rumor is true I didn't see that part coming!

Sex addict David Duchovny and his actress wife Téa Leoni have split up - but not for the reasons one might think.

It was not his 'sexual compulsion proclivity' that caused the break-down of their marriage, but rather his discovery of explicit text messages on her mobile phone sent by actor Billy  Bob Thornton.

Through the texts Duchovny found out she had begun a relationship with Oscar-winning actor Billy Bob Thornton, 53, who was formerly married to Angelina Jolie.

The couple are separating after 11 years and two children, daughter Madelaine West, 9, and son Kyd, 6.

Five-times married Billy Bob met Téa when they made a comedy film together earlier this year called Manure.

Thornton, a musician with his own band, has been seen with Téa at his gigs.

'She even helps him load and unload his truck,' says a friend of the couple.

Thornton, who starred as the U.S. president in Love Actually, has three children by his various wives, plus a four-year-old daughter by his current girlfriend, Connie Angland.

But he is reported as saying that he won't wed again because marriage 'doesn't work' for him.

It was Téa who persuaded her husband to receive treatment at the Meadows clinic in Arizona, followed by further treatment at the Keystone centre in Pennsylvania.

Miss Leoni cancelled a planned appearance at the Toronto Film Festival to promote her latest movie because of her husbands treatment.

'Yes, they have separated,' says Téa's spokeswoman.

'She is living on her own with the children in New York, but we did not want to announce it for the sake of the children until after David had received treatment for his problems.'

Duchovny, who plays a sex-obsessed writer on the television drama series Californication, which is shown in Britain on Channel Five, had faced rumours of sex addiction before he was married.

And a source close to the series said at the time that the news of his rehab was not a surprise.

They told Us magazine: Hes a guy who loves women. Hes always noticed an attractive lady.

Duchovny, whose summer X Files movie reunion with Gillian Anderson was a flop, is due to start work on the comedy, The Jones, co-starring Demi Moore, shooting in Atlanta, Georgia.