Britney Spears and Louis Walsh are ''BBFs'' since meeting on 'The X Factor' recently.

The judge got to swap from the UK to the US version of the talent show last week, standing in for head judge Simon Cowell - who was taken ill - and got on so well with new judge Britney, pals are saying they are now Best Friends Forever (BFFs).

Sinitta, a long time friend of both Louis and Simon, told Heatworld.com: ''Louis is absolutely besotted with Britney. I called him the other day and it's all he talked about. They're new BFFs, and they're in contact with each other a lot!''

When they were recently interviewed, Louis admitted: ''Britney and I are bonding.''

The 30-year-old 'Toxic' singer added: ''I have so much fun with him.''

The other judges on the US panel also took to Louis, with Demi Lovato saying: ''There is only one Simon...but Louis killed it.''

Fourth judge, L.A. Reid, who butted heads with the Irishman over one contestant, held no grudges, saying: ''I absolutely love working with Louis.I find him fascinatingly quick, thorough, and remarkably entertaining.''

Although Louis was a hit on the show, it looks like his appearance will be a one off, as Simon is set to return at the San Francisco auditions tomorrow (16.06.12).