Jamie Lynn upset by cheating boyfriend

Britney Spears' sister Jamie Lynn is reportedly devastated after learning that her unborn baby's father has cheated on her.

The Zoey 101 star, 16, announced that she is expecting a baby with student Casey Aldridge earlier this month.

However, reports claim that Aldridge has been seeing other women while dating Spears, including a girl named Whitney Seals from Mississippi.

Seals' brother Kevin told MSNBC.com: "Whitney and Casey have been dating for months. I know Jamie Lynn was really upset and jealous when she found out about it."

It was recently rumoured that Aldridge is being paid to act as a cover-up for the real father, who could face charges because he is an older man.