By Jason Lynch
July 17, 2006 12:00 PM

Jeremy Piven doesn’t have his own entourage, though plenty of people have been applying for a spot. During his June 8 visit to New York City hot spot Marquee, security was called in to protect Piven from the frenzied crowd, which surged toward his booth after spotting him. One night earlier, at a Buddha Bar party for the third season of Entourage—Piven’s inside-Hollywood HBO series—the actor was mobbed by women, many of whom were eagerly slipping him their numbers. “None of this is lost on me. I love it,” says Piven. “I’m having a great time.”

Who wouldn’t be? “For years he went everywhere unrecognized,” says Patty Jenkins, an occasional Entourage director. “His world has changed radically.” That’s all due to his role as Ari, Entourage‘s take-no-prisoners pit bull of an agent, which has finally made a star of Piven, 40, after years in second-banana parts on TV (including Ellen DeGeneres’s 1990s sitcom) and movies (as John Cusack’s frequent sidekick). “This is his moment,” says Joe Carnahan, who directed him in next year’s comedy Smokin’ Aces. “With that comes a certain amount of attention.” And a series of tabloid and Internet reports alleging a variety of partying and bad-boy behavior. New York City tabloids, for example, breathlessly recounted a June 6 altercation with Blade actor Stephen Dorff at the nightclub Bungalow 8; they exchanged heated words after Dorff, according to an eyewitness, cut in line for the restroom. “That anyone would think that is newsworthy is funny to me,” says Piven. “Who cares?”

Despite Piven’s reputation as an all-nighter, “he’s a sweetie,” says Adrian Grenier, who plays Vince Chase on Entourage. “Jeremy’s not at all like Ari.” Adds costar Debi Mazar: “I see him as someone on the vulnerable side but very flashy. He’s a peacock.” And if the tabloids ruffle his feathers, “I figure that it’s the tab you pay for this kind of success,” says Piven, adding that his social life has been exaggerated. “I’m not a machine. This last week, I worked until midnight almost every night.”

Still, his mother sounds worried. “His life is so stimulating right now that it can be a pitfall,” says Joyce (who cofounded Chicago’s renowned Piven Theatre Workshop with her late husband, Byrne). “He has to pace himself.” But the Evanston, Ill., native says he’s ready to make the most of his big break, which means marriage and kids will have to wait. “I want to take that step,” says Piven, who is single. “But how can you have a relationship with these hours?”

Instead he’s looking forward to winning over a certain female at her birthday bash the following day. “I’m always trying to impress that girl,” sighs Piven, who also voiced an Ari-like agent in Cars as part of his quest for her affection. Another tabloid scandal in the making? Nope, just his niece Lili Rose, 6. “What more do you want?” he says. “Good work and good friends; family. Who am I to complain?”