Kate Middleton is concerned that her pregnancy is not allowing her to dress in a manner that makes her look young due to her expanding figure.

According to friends, Middleton’s pregnancy, at its third trimester, makes it harder for the duchess to find styles that don’t make her look frumpy, and she has reportedly been buying more lingerie to look sexy for Prince William.

“Kate doesn’t want a frump bump,” a source told British magazine Now.

After British designer Lorna Drew sent her a slinky satin bra and matching underwear, the future royal mom was reportedly relieved.

“I couldn’t believe the response we got when we sent Kate the underwear,” said Drew. “We actually received a message from her office saying she was delighted with it.”

But according to the report, her husband has been assuring his wife that despite the bump, she still looks beautiful and sexy.

“William has always fancied very sexy women and that’s what attracted him to Kate in the first place. He was hooked from the moment she slinked down the catwalk at university in 2002 in a see-though black slip,” said a source.

However, the duchess is still concerned about looking attractive, admitting to friends that she finds it hard to balance her pregnancy with looking young, and is reportedly upset that some people have said that she’s been dressing like a grandmother.

“Her mistake is that she’s been trying to appear quite formal to impress the Royal family, but in private she really isn’t like that at all,” said the source.