07/06/2012 at 11:00 AM EDT
Are Rachel McAdams
and Michael Sheen taking their relationship to the next level – with a baby?
Not quite, although the actress has been sporting a faux bump on the set of About Time
, her latest film costarring Bill Nighy and Domhnall Gleeson.
In pictures taken while filming in London's Notting Hill neighborhood, an in-character (and dressed-down!) McAdams, 33 – who was first linked to
Sheen, 43, in 2010 – is sporting quite the belly.
The film, written and directed by British filmmaker Richard Curtis (Bridget Jone's Diary
, Love Actually
), tells the story of a man who travels back in time. The movie, however, is set to arrive in theaters in the future – in 2013.
Not that motherhood is not in the plan, though.
In 2009, she told PEOPLE
she was "looking forward to it some day. ... Having a few [kids] would be great," she said.