is dating Jared Leto
. The actor was caught giving the Dukes of Hazzard
star his number at Los Angeles nightclub Hyde on June 2 and then, four days later, the pair were seen getting cozy at another club, Double Seven. An insider revealed: "They are an item."
One onlooker added: "They were hanging all over each other."
Leto - who is best known for his roles in Panic Room
and the cult 90s teen drama My So-Called Life
- has previously dated a bevy of famous beauties, including Cameron Diaz
and Scarlett Johansson
However, Simpson's spokesman denies the 25-year-old blonde has added herself to that list, saying: "Jessica is not dating anyone. She is single. There is no truth to these rumors."
Jessica Simpson picture gallery