The Succession actor, 47, met Hawes, 45, on the set of BBC series Spooks in 2002. They married two years later.
When asked by The Times about successfully sustaining a marriage despite the acting profession having higher divorce rates, he acknowledged that it wasn’t easy.
“You can get quite close to the actors you’re working with and all that stuff,” he said, adding: “It’s odd.”
Macfadyen was then asked about Bodyguard, the BBC hit in which Hawes’ character had sex scenes with Game of Thrones actor Madden.
Responding to whether he found it “comfortable” seeing “your wife in other men’s arms”, the actor said: “It’s just weird. It does [touch a nerve] a little bit.”
However, he said it helps that filming a sex scene “is the least sexy thing you can possibly imagine”.
Macfadyen emphasised the importance of intimacy coordinators, who make sure co-stars are comfortable while filming such scenes.
“I wish we’d had them,” he said. “Because then you’re not afraid to go, ‘I don’t want to do that.’ It sounds OTT, but it’s a healthy overcorrection, because it takes away the pressure to take off all your clothes, or do stuff you didn’t want to do.”
Macfadyen plays Tom Wambasgans in Succession, which is currently airing its third season.
His previous credits include Pride and Prejudice, Frost/Nixon and The Assistant.