They have since been keeping their relationship in secret, and are rarely seen in public.
The Mean Girls actress and Dear John writer Linden, 37, were first romantically linked in April 2016, and, like they did with her pregnancy, have kept a relatively low profile throughout their relationship.
David and Rachel were first linked in 2016, news about an alleged came out in August 2017.
A fan of Curtis for years, McAdams wanted to work with him on what he stated would be his last project as a director.