Anna Friel thought her relationship with ex-partner David Thewlis would "last forever".
The 35-year-old beauty - who split up with the 'Harry Potter and the Deathly Hallows' actor late last year after 10 "wonderful" years together - is now dating 'Notting Hill' star Rhys Ifans, but she found her former flame to be a "fantastic influence" on her life.
She said: "I was 23 when I got together with David and had a very different way of looking at life. I grew and he was a fantastic influence on me and we spent 10 wonderful years together. And then we both just decided that we'd become friends as opposed to lovers.
"I thought the relationship would last forever, but as you get older you realise that certain relationships are for certain times."
Despite the pair - who have daughter Gracie, six, together - never tying the knot, the 'Pushing Daisies' actress thinks of their relationship as if it were a marriage.
Anna added in an interview with Tatler magazine: "I can't really look back and go, 'What if?', but I think there is something to say, 'I do'. Because no matter how difficult things get, well, sorry, but we're married."