Pregnant teenager Jamie Lynn Spears has a diamond ring on her finger, but there are still obstacles to overcome before she and Casey Aldridge, 18, can be married. Her mother, Lynne Spears, has insisted that the couple sign a prenuptial contract to protect the Zoey 101 star’s assets. “The contract is already drawn up and ready to go,” an insider confirms to In Touch. “Lynne’s not sure marriage is a good idea, but she’ll go along with that if that’s what Jamie Lynn wants — as long as Casey signs the contract.” A Spears family confidant says that Lynne, who flew home to Kentwood, La., to celebrate Jamie Lynn’s April 4 birthday, is worried about Casey. “He doesn’t seem as committed to the relationship as Jamie Lynn,” says the confidant, adding that the family is aware of the rumors that he’s cheated. “Lynne is keeping an eye on him.”

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