Things aren't well between Britain's Got Talent 2013 judges Simon Cowell and David Walliams!
At least according to those anonymous "sources".
Insiders have claimed that Simon's not been too impressed with some of David's more personal jokes,which have included yet more digs at his love life and sexuality.
The pair clashed at try outs in London, with a source claiming: "Simon was fuming he thinks David's jokes are good fun most of the time, but when it gets personal, he draws the line.
"He's told David he needs to keep his mouth firmly shut on such matters as his private life."
Speaking to Star magazine, the source added: "Simon doesn't like being made to look silly. he won't stand for it"
Perhaps he should ditch the stacked heel shoes and ripped jeans then!
Simon previously admitted he was dreading David's inevitable gags and jokes at his expense.
The music mogul confessed before the first auditions in Wales last month: “I’m actually dreading David. I woke up this morning thinking I’m not looking forward to this.”
Browse our gallery from the first BGT 2013 auditions below...