Things were rather chilly between Pamela Anderson's former husband Tommy Lee and current boyfriend Kid Rock at the fifth birthday party for Anderson and Lee's son Dylan on Dec. 29 at Pamela's Malibu, California beach house, reports Us Weekly. A guest at the party told the magazine: "Kid and Tommy didn't really speak to each other." According to the insider: "Pamela had a way of strategically keeping them at opposite ends of the party at all times." Plus, she kept stressing to Rock that "this was Dylan's day, and she wanted it happy and fun." Among the other guests at the party was neighbor Cher, who is said to have stopped by for a slice of the birthday cake.