He may regret this... It's never good to go on a rant about your ex-mother-in-law but to do so publicly is 100 times worse. It didn't seem to bother Laurence Fox though as he used one of his recent gigs to vent some anger towards his soon to be ex-mother-in-law. According to The Sun, while on stage he launched a rant about Billie Piper's mother saying."This is a song about my soon to be ex mother-in-law. I s*** you not. I s*** you not.” But he didn't stop there. "She’s a wonderful woman actually, I’ve got no beef with her. Do I? Yeah I do, I’ve got a beef with her, man.” An insider told the site, "There was always a clear culture clash between Laurence and Billie due to their different upbringings. Their families have never seen eye-to-eye and issues rose on a number of occasions throughout their relationship. “It is no secret that Billie has had an up-and-down relationship with her own parents too. However, Laurence has always been a private guy and it is a shock to hear him speak so candidly about Billie’s mum in front of hundreds of people.” Well you can be sure their families won't see eye-to-eye now anyway.