Matthew Morrison Fired from SYTYCD for 'Flirty' Messages That Made Contestant 'Uncomfortable': Source

New details are emerging about Matthew Morrison's sudden departure from his judging gig on So You Think You Can Dance.

A source close to the Fox reality show tells PEOPLE that Morrison, 43, was fired from the series "after he had an inappropriate relationship with a female contestant."

"They didn't have sex, but he reached out to her through flirty direct messages on social media," the source says.

"She felt uncomfortable with his line of comments and went to producers, who then got Fox involved. He was fired after they did their own investigation."

The source adds that Morrison and the unidentified female contestant "never met up off-set."

"It was just messages that crossed the line," the source notes.