Jessica Simpson: 'I'll Spoil Ashlee's Baby' 9/9/08

Jessica Simpson can't wait for her little sister Ashlee to give birth - because she wants to "spoil the kid rotten".

The Outta My Head singer is expecting her first child with Fall Out Boy rocker Pete Wentz - and Jessica is ecstatic at the prospect of becoming an aunt.

She says, "I'm going to spoil the kid rotten, that's for sure.

"I think my sister's going to be pretty strict, actually, because she's been so good throughout her pregnancy. She's just such a woman. I'm like, 'Oh, my gosh - what's happened to my sister?'"

And the 28-year-old has quashed rumors that Ashlee is expecting more than one baby, adding: "Definitely not twins!"

The couple is expected to welcome the new addition in October (08).