The ENQUIRER exclusively reports the night before Jamie Lynn Spears gave birth, fiancé Casey Aldridge was out candoodling another woman!

On the night of June 17 – the night before Jamie Lynn’s C-section – a source says Casey was at Bates Bridge, a popular hangout for singles — with an old flame.

“Casey and an old girlfriend were hugging in a more than friendly way,” an eyewitness revealed.

“Once people started to notice and pay attention, they quickly moved into a parked truck with tinted windows.”

Later, the two emerged, “laughing and flirting late into the night”.  They were “all over each other,” added the eyewitness.

While surfing the Internet at her mom’s home, Jamie Lynn discovered photos of Casey with another woman, which led to a huge fight between the young couple.

Since their blowout, Casey has spent much of his time partying with his buddies while Jamie Lynn cares for their child alone.

“Jamie Lynn is really upset and frustrated,” said the insider. “This isn’t how she hoped her life was going to be.

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