Uh, who could blame them?
Shia LaBeouf admits that he hooked up with Megan Fox while making the Transformers films -- and he's not sure whether or not his sexy costar was attached at the time to then-boyfriend Brian Austin Green, now her husband.
Nodding in the affirmative about a hookup with Fox, LaBeouf explains in a new Details mag interview, "Look, you're on the set for six months, with someone who's rooting to be attracted to you, and you're rooting to be attracted to them."
Without giving specific dates or details, the 25-year-old actor (now dating Hollywood stylist Karolyn Pho) continues of the fling: "I never understood the separation of work and life in that situation. But the time I spent with Megan was our own thing, and I think you can see the chemistry onscreen."
When Details asks him about Fox's status at the time with Green, he sputters. "I don't know, man. I don't know. I don't know. I don't know," he says, repeating "I don't know" eight more times. "It was what it was."
Fox, 25, wed on-and-off beau Green one year ago in Hawaii. She was famously replaced by Rosie Huntington-Whiteley for Transformers: Dark of the Moon, out next month. (Director Michael Bay and LaBeouf recently confirmed that Fox's controversial comments about Bay, comparing him to Hitler, got her dropped from the franchise -- at the direct order of executive producer Steven Spielberg.)
LaBeouf also opens up about other failed romantic entanglements. His one date with Hilary Duff was "probably the worst date either of us have ever had."
He also fesses up to "philandering around" with former co-star Isabel Lucas. "It was sort of disastrous...Neither one of us, I think, were in love. Just sort of experimenting or whatever."
On his ex-girlfriend Carey Mulligan, with whom he parted ways in October 2010: "I still love her...I think she's a fu**ing awesome person and an incredible actress. We're still pals. I wouldn't take any of it back, and I don't think she would either. It just ran its course."