A U.S. magazine is reporting that Britney Spears and ex-husband Kevin Federline have been engaging in late night phone sex over the past few weeks.

Whilst their custody battle over sons Sean Preston and Jayden James very publicly rumbles, in private the former couple have apparently been getting reacquainted with the help of some long-distance dirty talk.

“They have phone sex pretty often-at least once a week…The one thing those two have in common is their need for sex,” a source dishes to Star.

“She often contact Kevin on Monday nights, usually because she’s recovering from a lonely weekend and feeling insecure...He knows just how to get the sultry talk started. Kevin is long-winded and can go on forever!”

Despite persistent rumours of a possible reconciliation between the pair, phone sex is where Britney is drawing the line - for now.

The insider adds, “Britney won’t have actual sex with Kevin because she’s so afraid of opening that door. To have physical intimacy would be a lot for her to handle right now.”