The Sitter's Tale; Jude Law and Sadie Frost

New faces at the National Portrait Gallery: the star of 'eXistenZ' and his wife, an actress, celebrate their anniversary in the red room

JUDE LAW: Sadie and I had our paper wedding anniversary last year, and she had the idea that she wanted to have our picture done. She knew my sister was a really good photographer and they worked in cahoots to set the whole thing up without me knowing. Sadie was really into the whole thing, and they wanted the photo to be spontaneous, but I was in a bad mood, which sets an atmosphere in the picture. I like that, rather than it being too formal.

Because Tash took the picture, it was definitely shields down. I didn't want to pose so I started taking the mickey. Sadie is quite comfortable posing; I'm not, but I often find I like the finished product. We are on the sofa in our red front room, and a print of the photograph now hangs there. You can see an energy between us. I like the idea of being able to see it in years to come.

I'm a great lover of portraits, but it's rather funny entering the world of your own portrait - it's almost therapeutic, seeing inside yourself. This photograph reminds me of a Hopper painting - the slightly elevated angle, and the window with the sun coming through.

SADIE FROST: Portraits have been out of fashion, but I thought it would be really good for our children to see a portrait of us. I didn't want it as an egotistical thing; it's just representative of the year, like the trainers Jude is wearing.

Everything in the room is red, so I thought it would be really good to wear a red dress. The project was a secret from Jude - he didn't know it was going to be an anniversary present - and he got upset because I had this beautiful dress on and he looked scruffy. So he was sulking which I think added character to the picture. Our kids and his best friend were trying to cheer him up, but if he had dressed up, it would have been too contrived.

Our living room is quite Seventies, and the picture is in a way. It's slightly Hockneyish - friends have said it's like Mr and Mrs Clark and Percy - so it really fits in.

Natasha Law's 1998 portrait is part of 'Bright Young Things', from 4 June. National Portrait Gallery, WC2 (0171 306 0055)