Anne-Marie Duff accidentally joked about her sex life with Prince Charles.

The 49-year-old actress - who has son Brendan, 10, with ex-husband James McAvoy - made the gaffe when the prince asked her and her then-spouse if their respective careers left them with little time for one another.

She recalled: ''My most embarrassing moment involved Prince Charles. I was at a premiere with my ex-husband.

''Prince Charles said, 'I suppose you two never see each other.' I said, 'We see each other in bed.' ''

The 'Salisbury Poisonings' star gets starstruck around musicians she admires and would rather not speak to them if they're in the same room.

She said: ''I only get starstruck around musicians. If I'm in the same room as Elvis Costello or Rufus Wainwright, I want to fall off my chair. I never approach them - I don't want to burst that bubble.

''I love how fandom makes you feel 15 again. If someone feels 'other', I don't want to pedestrianise them.''

Despite her years of success, Anne-Marie worries it will all come to an end because she's never fully felt like she belongs.

She admitted to Observer magazine: ''I suffered from impostor syndrome when I was starting out. I come from a working-class background and often felt like I didn't belong.

''That never leaves you completely. Even the most successful actors have this constant worry that a timer is about to go off and the jig will be up.''

The former 'Shameless' actress believes the most important thing in life is love.

She said: ''Love is the key to happiness. Coming from a very poor background, I know that money makes life a lot easier. But love is more important. To know that you're loved, to know you're worthy of love, to have love around you, to give love - that's all we can hope for.

''Happiness is fleeting. There are hills and valleys. But if you can lean on love, then you're safe.''