BRITNEY SPEARSand her husband KEVIN FEDERLINE's love knows no bounds in the studio - they've just recorded a series of duets during a marathon singing session. Federline hopes the collaborations will eventually kill tabloid reports the pair is set to split. The dancer/rapper is so impressed with one of the duets he has selected it to feature on his debut album PLAYING WITH FIRE, but he won't divulge its title. He tells USA Today, "It's not really a love song. It gives my point of view on how my family is and how tight my family is. "People shouldn't believe what they're told about us. They should listen to what comes out of my mouth and what comes out of my wife's mouth." The couple, who have been married for two years and are expecting their second child in September (06), have been a frequent target for the tabloid media. Federline adds, "Even with the bad stuff, you go through it, and it just makes you love each other even more. Well, in our case at least."