And another one bites the dust. Rachel McAdams and Michael Sheen are dunzo.

A source confirmed to Us Weekly that McAdams was the one who broke things off.

The couple, who met on the set of Woody Allen's 'Midnight in Paris,' first went public in October 2010, but the Canadian-born McAdams, 34, insists they didn't shack up until filming wrapped, saying, "Michael and I didn't get together while we were filming ... which I feel strongly about not doing when I'm working."

"We became quite good friends, which I think is a great way to start. I felt very blessed to have made a Woody Allen film in Paris together."

Sheen, 44, was described as one of McAdams' "best friends," and the duo put in work on the relationship, but it seems it just fizzled out.

"Michael and I never spend more than three weeks apart -- we rack up a lot of air miles -- but you have to be quite adaptable in this business whether you are in a relationship or not," McAdams explained.

It's a bit of a bummer because McAdams is so lovely, but now we're holding out hope for a Ryan Gosling reunion. Sorry, Eva Mendes -- you don't mess with 'The Notebook.'