A source tells the Daily Star, "Calum was quite brave calling Britney as he only met her briefly a few years ago but when her people told her he’d been in contact, she was happy.

"Calum said he was worried that Lindsay would be so lonely at Promises that she wouldn’t benefit from the treatment at all. Britney’s now in such a good place that she said she’d be happy to visit and to introduce Lindsay to some of her friends there."

He’s even said to be in the process of renting a condo near the Malibu rehab centre.