Snitching sources are dishing that Jessica Simpson is feeling a little threatened by her baby sister these days.

The Employee of the Month actress is said to be very unhappy that younger sister Ashlee’s fame is beginning to surpass her current B-List status.

“Jessica finds it tough being compared with Ashlee, who’s becoming a big star and is threatening to overtake Jessica as the more successful sister….Jessica was always seen as the bigger star, but now Ashlee is taking over. There’s certainly a sibling rivalry between them,” a tattle told Closer Mag.

Since she began dating Pete Wentz about a month ago, twenty-two year old Ashlee has become a paparazzi haunt and a regular on the Los Angeles party scene.