Los Angeles - George Clooney, 52, and Stacy Keibler, 33, allegedly "hadn't had sex in months" before their break-up.
Clooney and the former WWE wrestler broke up after just over two years of dating.
They allegedly called it quits over the phone after a serious dry spell between the sheets.
A source told the upcoming issue of Us Weekly magazine: "They hadn't had sex in months. He's been in Europe, and she's in LA, and they haven't seen each other in a long time. Some girls would be OK with that and just be happy dating George, but not her."
The Hollywood hunk and Stacy are said to have ended their relationship on amicable terms, after drifting apart over the last three months.
This happened while George was in Europe working on a film and Stacy stayed in Los Angeles for her new TV show Supermarket Superstar.
It has also been claimed that Stacy was keen to get married and start a family, while George wasn't ready to fully commit.
A second insider revealed: "She knew he wasn't looking to get married. But there was always that fantasy that he would commit. Sadly, it just ran its course."