But unlike her relationship with The Notebook's Ryan Gosling, McAdams tells The Sunday Telegraph's Stella she waited until production wrapped on Midnight in Paris before taking the next step with Sheen, 42.
"Michael and I didn't get together while we were filming Midnight in Paris, 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," McAdams says. "I felt very blessed to have made a Woody Allen film in Paris together."
Calling Sheen "a very funny person," McAdams admits it's hard being away from her actor beau when she's shooting a movie.
"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," The Vow star says. "Trying to establish roots somewhere is a bit of a joke."
McAdams' most important relationship rule? "You need to trust each other and be able to talk to each other and be best friends."