United Kingdom, Oct. 4 -- Penny Lancaster once "tried" Botox without telling her husband Sir Rod Stewart.

The 54-year-old model tried the non-surgical treatment - which smooths out wrinkles - before she got married to the 80-year-old rock star in 2007, but Rod knew she had something done because Penny's facial "expression" changed.

Asked how she is "coping" with the ageing process while being in the public eye, Penny told the new issue of Woman magazine: "I'm quite self-conscious about the weight I've put on, and I wonder who is this older woman I'm seeing now, especially when I look at my phone and the camera comes on!

"I tried Botox just before I got married. And it worked. But I hadn't told Rod, and he noticed.

"He said, 'Your whol...