Amy enjoys the sun with her ex-boyfriend as husband Blake sits behind bars

As her husband remains behind bars, troubled singer Amy Winehouse has been enjoying herself in the Caribbean with an ex-lover, I can reveal.The 24-year-old has been relishing the sand and surf with her former flame, music manager George Roberts, during her winter holiday in the sun-drenched paradise.The news is likely to come as something of a surprise to Amy's husband Blake Fielder-Civil. Blake, 25, who is on remand in Pentonville prison for alleged assault and conspiracy to pervert the course of justice, is already said to be jealous of Amy's close relationship with George."Blake will go mad that Amy has been out with George as he feels quite threatened by their close friendship," a source close to Blake tells me."He won't like it at all that George has been away with Amy." Friends said that George, who lives with his girlfriend in East London, was with Amy for the first part of her holiday. She is now staying at singer Bryan Adams's house in Mustique."Amy loved having George on holiday with her," a source close to the drug addicted singer said last night."She absolutely adores him and they had a great time larking around in the sun."She has been speaking to Blake when she can and making out that she has not been having a great time."She doesn't want to rub it in that she's having fun while Blake's in a cell. "The truth is Amy and George have been having a blast. They used to date and had a very passionate love affair. They are still very close, Amy wouldn't have invited him otherwise."Amy and George, who works for a music-management company in Central London, were briefly linked two years ago. They were photographed kissing passionately in the back seat of a car at an after-party following the Brits."George has been a rock for Amy over the past few months," adds the source."They speak all the time and are incredibly close."A spokesman for Amy last night confirmed: "They're old friends and they met up on holiday."