Ashlee Simpson expecting twins?

Ashlee Simpson and Pete Wentz

Ashlee Simpson is reportedly expecting twins with husband Pete Wentz.

The 23-year-old singer and her Fall Out Boy rocker beau are set to welcome two babies into the world later this year, according to Pete's musician friend Tyga.

Hip-hop star Tyga told gossip website E! Online: "Pete and Ashlee are having twins. They're really happy."

This is not the first time it has been claimed the couple are expecting two bundles of joy.

In June, Pete, 29, accidentally referred to the baby as "them" during a radio interview, causing fans worldwide to speculate Ashlee is carrying twins.

Ashlee - who attended the MTV Video Music Awards in Los Angeles last night (07.09.08) - explained how she manages to maintain her looks during her pregnancy.

Speaking on the red carpet, Ashlee said: "It's the three Bs - the boobs, the belly and the booty. When you are choosing dresses, you have to pick ones that don't stick to your belly."

The singer's representative has refused to confirm reports the couple are expecting twins, saying, "It's not true" when confronted with the rumours.