Heidi Klum and Tom Kaulitz. Picture: Reuters

Heidi Klum is tired of the age gap between herself and her boyfriend being "shoved" in her face.

The 45-year-old model is dating Tom Kaulitz - who, at 28, is 17 years her junior - and she admitted the only time she's ever quizzed about getting older is when people question her romance with the Tokio Hotel musician, but she isn't bothered about their opinions.

She told InStyle magazine: "I don't really think about getting older that much -- I mean, know it's happening to me, it's happening to all of us. But it's not like I wake up in the morning, look in the mirror, and say, 'Oh my God, oh my God.'

"Lately, I'm being reminded more about my age by people other than myself.

"My boyfriend is many years younger than me, and lots of people are questioning that and asking about it. That's really the only time when age seems to be shoved in my face and I have to give an answer for it.

"I don't really think about it that much otherwise. You have to just live a happy life without worrying too much about what people think because worrying is only going to give you more wrinkles."

The 'America's Got Talent' judge - who raises four children, Leni, 14, Henry, 12, Johan, 11, and eight-year-old Lou, with ex-husband Seal - has grown used to the scrutiny she comes under in the public eye and even though sometimes she's subjected to cruel comments, she's learned to see the funny side.

She said: "Sometimes they'll compare a photo of me from 10 years ago, right after I had a baby, with a photo of me right now, and say, 'Oh, she was curvier then, or her boobs were so much bigger.' 

"Yeah, they were so much bigger because I was breastfeeding! And I probably really needed to pump right then. You just have to come to terms with it."