The former couple reunited – with a kiss! – at London's Heathrow Airport on Wednesday.
The rendezvous came just three weeks after they stepped out together for lunch in Malibu alongside Cox's daughter, Coco.
"They really care about each other and they're spending time together," Cox's rep told PEOPLE in March.
Cox, 51, and McDaid, 39, got engaged in June 2014 after six months of dating, but one source told PEOPLE that there were longtime problems between them; and in December they revealed they had called off the engagement.
But in April 2015, Cox told PEOPLE of the Snow Patrol guitarist, "When I knew that this was just who he is, that he was just a beautiful, sensitive, loving person with a wonderful family, with a beautiful set of friends. Then I was like, 'This is for real!' "