It’s take two for Kiefer Sutherland and his ex-wife, former model Kelly Winn.

“He’s been sneaking up to her house in L.A. and spending a lot of time with her,” a source tells Star.

While the duo split in 1999 after three years together, their divorce wasn’t finalized until May 2008 because they were hoping to reconcile. Twice-wed 24 star Kiefer, 42, later romanced magazine editor Siobhan Bonnouvrier — but when that relationship began to fizzle in late summer, he raced back into 48-year-old Kelly’s arms.

“She really understands him and his quirks, and once the pressure was off to fix the marriage, he relaxed and became more open with her,” says the source. “He’s finally realized he never should have left Kelly.”

Adding: “It’s still in the early stages, but Kelly hopes it will work this time.”

Source