But he has shared his thoughts on extramarital affairs in the past. In a 2016 interview with the Evening Standard newspaper that has now resurfaced, the actor said women should "turn a blind eye" to brief affairs.,.
Discussing his TV series The Affair – which he starred in from 2014 to 2019 – West said:
"I think women should be more indulgent of affairs. I really do. It's daft to kick someone out over a fling. Isn't it?"
"Everyone should turn a blind eye to men's behaviour between the ages of 40 and 50. Let it all blow over."
West played the role of Noah Solloway in the show about a married man who begins an extramarital affair with a younger woman.
There were a fair share of sex scenes in the series, which West said his wife didn't wish to tune in for but was accepting of.
"If Catherine was in something like that I would not be happy. But she's OK with it. She's cool," he said.
"She saw a bit of it on the plane once, and I saw a bit of it on the plane. Neither of us watches it. Can't bear to — although apparently it's quite good."
Before his marriage to FitzGerald, the actor was in a relationship with Polly Astor, with whom he shares a child.
West and Astor – who is the daughter of British politician Michael Astor – had a baby girl, Martha, in 1998.
In a 2012 interview with MailOnline West, who got his big break playing Detective Jimmy McNulty in The Wire, admitted their break-up was his fault.
"It was terrible because it was all me. I wanted out," West told the MailOnline.
"I hurt Polly very badly, but at the time I wasn't ready to settle down. I was two years out of drama school and things were going really well. I was doing films all over the place and didn't want to be tied down. Then I got The Wire.
"Martha was about three when Polly and I split up, and The Wire was very much a part of it.
"Women were extremely important to me and I wanted to be selfish for a bit longer. I wanted to play the field, I suppose."
West went on to rekindle his romance with Irish landscaper FitzGerald, who he had dated in college for three years in the early '90s.
West wrote in the Irish Independent in 2016 that he was infatuated with FitzGerald, who had caused "quite a stir" on campus due to her beauty and intelligence.
But the couple split after college and FitzGerald went on to wed Viscount Lambton, the 7th Earl of Durham, in 1995, but they divorced in 2002.
West and FitzGerald reconciled not long after and became engaged in 2007.
FitzGerald was born into an Irish royal and aristocratic dynasty that originated in Normandy and dates back to the 14th century.
Her father was Desmond FitzGerald, the 29th Knight of Glin, who died in 2011. Given he had no male heirs, with three daughters, the title became dormant upon his death making him the last Knight of Glin.
FitzGerald and her sisters bought their father's 800-year-old, 18-bedroom hereditary castle, Glin Castle, on Ireland's coast after his death to keep it in the family.
FitzGerald and West now visit the home with their friends and family, and occasionally rent it out to guests for special occasions, with Taylor Swift among their glittering visitors.
West visited the castle for the first time for FitzGerald's 21st birthday when they were studying at Trinity College together.
It is also where the couple were married back in 2010.
"I was really struck by the romance of the place," West told Architectural Digest last year, with FitzGerald revealing Mick Jagger was among her father's many high profile guests at her childhood home.
"My parents were part of the whole swinging '60s art scene in London and Dublin and they had friends in all kinds of worlds. My dad would invite totally opposite people, like priests and poets and rock singers, all mixed up in a crazy hodgepodge. Everyone loved it."
West and FitzGerald have four children together, Dora, 13, Senan, 10, Francis, 9, and 5-year-old Christabel.
