REVEALED: Ryan Phillippe's Estranged Relationship With Ex & Mother Of His Daughter, 'Pitch Perfect' Actress Alexis Knapp

Cruel Intentions star Ryan Phillippe and ex-girlfriend Alexis Knapp welcomed their only child together back in 2011, and insiders close to the actor claim he and the Pitch Perfect actress have remained estranged since the birth of their baby girl.

"Ryan questioned whether the child Alexis was carrying was his and wanted a paternity test," one pal said.

RadarOnline.com has exclusively learned the duo allegedly have led separate lives in the years that followed. The Shooter actor has never been photographed with their daughter, Kai, and a friend said his contact with their little one is sporadic.

Alexis is Ryan's third child, and she was born after the famous former flames ended their short-lived relationship in 2010. The former soap opera heartthrob is also father to two children, son Deacon and daughter Ava with ex-wife Reese Witherspoon, both of whom he often speaks out about with pride.

"I just don't think Ryan ever really felt a connection there," claimed a source. "He and Alexis were never that serious as a couple."

"Alexis is happy to raise Kai as a single mom and she makes no demands on Ryan," the insider further alleged. "But we tell Ryan that as he gets older, he might regret not being a major presence in his daughter's life."

RadarOnline.com has reached out to reps for Phillippe and Knapp for comment.

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One year after she had their baby girl, Knapp gushed about their daughter's milestone during an appearance at the Chrysalis Butterfly Ball.

"She actually today stood up and stood there for like 20 seconds," the Project X starlet happily shared at the time. "I was like, 'Are you going to walk?! What are you doing?"

"I think she can do a lot more than she realizes, but she's amazing and she says my name all the time," Knapp added, revealing her daughter had similar physical features. "They always come out looking like the dads," she quipped.

Phillippe, for his part, was recently asked about the comparisons fans often make to himself and his two children shared with the Legally Blonde star.

"What I get a lot lately is they think Deacon looks like her and Ava looks like me," he told Extra in 2022, joking with a laugh. "My response is always, 'Duh … How are you surprised that children look like their parents?'"

As for Witherspoon, she also shares son Tennessee James with now-ex Jim Toth.