Nicole Richie’s father, R&B legend Lionel Richie, remains clueless as to why Paris Hilton and his daughter have stopped talking, but he’s confident that whatever the problem is, they’ll resolve it, according to a published report. Lionel Richie, whose daughter Nicole and her (former) best friend Paris have been inseparable since they were babies, told a radio station in Boston, Massachusetts, that he and the Hiltons are still close, and is convinced their daughters will patch things up.

He explains, “They have been having arguments since they were three.”

“My mother gave me some good advice: ‘As parents, if we can just stay out of our kids’ arguments, nine times out of 10 it will take care of itself.’”

The former pals stopped being friends in January of last year for unknown reasons, but Paris insists, “Nicole knows what she did.”

Lionel says, “We may never know what it is and you know what? Certain things we just don’t want to know.”