Denise Richards and Nikki SixxAlthough Denise Richards likes to date bad boys, she has learned that they are not the best bets for serious relationships. After a four-year marriage to actor Charlie Sheen, then a two-year twirl with Bon Jovi guitarist Richie Sambora, her recent romance with Motley Cru rocker Nikki Sixx was more for fun.

"She does like the bad boys, but the relationship with Nikki was just for fun and was never intended to be forever," a source close to Richards tells PopEater.