Because Her Wedding Is Officially Off:

From July 23rd issue of Star...

"Jamie Lynn and Casey have been fighting non-stop about everything, from what to name the baby to what to eat for dinner," a source tells Star. "And now she's called off their wedding plans."

Despite reports that the couple bought a house near Jamie Lynn's hometown of Kentwood, La,. Star has learned that 17-year-old Jamie Lynn has moved back into Serenity, the Spears' family estate — and her dad, Jamie Spears, has flown from sister Britney's side in L.A. to be there for his younger daughter.

"Jamie Lynn, Jamie and her mom are all staying at Serenity right now," a second insider reveals. "They've been busy decorating the baby nursery."

Casey, 19, is "in and out," the second insider says. But despite the couple's frequent trips to Wal-Mart, their relationship is seriously strained — and it's been the talk of the town.