The co-stars, both 25, enjoyed a brief fling while filming the science fiction action movie in 2006, although Shia claims to have no knowledge of whether Megan was still with her then-fiance and now-husband Brian Austin Green at the time.
He said: “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. 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.”
Asked if Megan and Brian – who got engaged in 2006 and broke up in 2009 before reuniting and marrying last year – were together at the time of their fling, Shia told Details magazine: “I don’t know, man. I don’t know. I don’t know. I don’t know. It was what it was.”
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After his brief relationship with Megan, Shia dated Carey Mulligan and although the couple are no longer together he admits he still loves her.
He said: “I still love her. I think she’s a f**king 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.”
However, Shia had less kind words for Hilary Duff calling his date with her “probably the worst date either of us have ever had” and revealing his “philandering around” with former co-star Isabel Lucas was a disaster.
He said: “It was sort of disastrous. Neither one of us, I think, were in love. Just sort of experimenting or whatever.”