The Mortal Instruments: City of Bones actor - who has been making audiences swoon with his shirtless scenes in TV drama 'Poldark' - and the 'Burnt' actress recently ended their relationship but have remained friends.
Confirming the split to the Daily Telegraph, Aidan refused to go into detail and said: "I like to keep my private life private for my own head. It's important to me that people don’t know too much about me because I'm trying to play characters. Sometimes you see actors who are really good, but you have trouble separating that actor from the celebrity profile. I don't want to be one of those guys. It helps that people don't know a lot about me, I guess."
The former couple had been dating for five years and Aidan previously revealed he was considering moving to New York to be closer to Sarah.
He said: "I'm thinking of moving to New York soon. That's the great thing, as an actor these days you can be anywhere because a lot of meetings are on Skype. It's not like 10 or 12 years ago when all the Irish actors were in London. Now you can be in a city for reasons other than your career."