It turns out that Jennifer Aniston isn't the first Hollywood star that Justin Theroux has hooked up with.
Jen's current flame once dated Who's The Boss? beauty Alyssa Milano, and the new issue of Star magazine has exclusive details on their hot relationship.
The tall, dark and handsome actor and the pretty sitcom star had a whirlwind romance after they met in the mid-90s and hit it off immediately, a source told Star.
"Justin was always ambitious, so his involvement with an established actress early in his career wasn’t a big surprise," the insider revealed.
Then an aspiring actor, Theroux, now 40, met Milano, 38, on the set of 1997 thriller Below Utopia where their roles as an on-screen couple led to a real-life romance when sparks flew during steamy love scenes.
Justin went on to embark on a 14-year relationship with fashion stylist Heidi Bivens, who he reportedly ditched for the Horrible Bosses star earlier this year.
Star goes on to reveal that Theroux might have had a similar cross-over with Milano, as he'd been dating an actress named Kathryne Dora Brown who coincidentally was friends with Alyssa around the time the pair met.
The full story is in the new issue of Star magazine -- on newsstands Thursday.