Pippa Middleton, the sister of Kate Middleton (aka the Duchess Cambridge), who turned 28 on Sept. 6, couldn't celebrate her birthday in style.

Amidst the rainy weather, Pippa enjoyed her birthday morning with her cup of coffee along the way going to work. Pippa was seen carrying her umbrella and her briefcase.

Pippa's sister is the beautiful and brilliant Kate Middleton, the wife of Prince William, the heir to the British throne. Kate was in London but there was no plan for celebrating her little sister's birthday.

There was no game or party for Pippa, who turned 28 on Tuesday. However, Pippa was spotted having lunch and enjoying shopping with a new mystery man. It is posssible that Pippa bought some birthday gift.

Pippa has gained worldwide recognition for being the Duchess of Cambridge's sister.

Hopefully, Kate Middleton had some plans to celebrate her little sister's birthday. Happy Birthday to you, Pippa!