Lily Allen Pregnant: Singer Expecting Second Child in December (Reports)

When Lily Allen took the stage last weekend in Manchester, England, for a surprise performance with Professor Green, she rocked a baggy Stone Roses T-shirt. This made sense, since the reunited British rockers were headlining the show, but she may have had another reason for the oversize wardrobe: She's pregnant.

According to The Mirror, Allen and her husband, Sam Cooper, are expecting their second child in December. The British pop star gave birth to daughter Ethel Mary in November, and while she's yet to confirm the news, she's reportedly been telling friends and family.

"It was a surprise but Lily and Sam are thrilled," a source told the U.K. newspaper. "The pair of them have loved every minute of ­parenthood so far and wanted to expand their brood quickly. So it's great timing."

Allen apparently won't let pregnancy affect her return to music, and now that she's back in the game following her retirement in 2009, The Mirror reports, she plans to spend the summer working on a new album she hopes to release next spring.

"Lily's got lots on her plate right now," the source told the paper. "She's been working on a handful of songs already and has lots more ideas of what she wants to do."