In images obtained by TMZ, Kevin, 68, had his arms wrapped around the star's waist as she sat on his lap while visiting Richard Branson's Necker Island in the British Virgin Islands.
They were both there to attend a tennis fundraiser for the Inspiring Children Foundation which was founded by Jewel.
Kevin was a guest at the event and looked more than delighted to be there with the striking singer, who at 49, is 19 years Kevin's junior.
The outlet also reported that the pair flew to the Caribbean together but kept their romance under the radar for the most part.
Jewel brought her son, Kase, along with her and mentioned him, Richard Branson, and Kevin in the caption of an Instagram post detailing her visit to the island. "A little late posting," she wrote alongside a montage of photos from her trip.
"Every year, my foundation @inspiringchildren and I go to Necker Island to help host a tennis event w @richardbranson to raise funds for our kids.
"Amazing players like @geniebouchard come and support us in playing doubles with the folks who come… it’s an incredible time, and one I use to relax, rest and play w my son! @kevincostnermodernwest was kind enough to mentor our kids this year, and Sir Richard was his usual inspiring self- who also plays a mean game of doubles."
Kevin and Jewel's connection comes after a difficult time for Kevin, who was embroiled in a challenging divorce from his ex-wife, Christine - who is also 49.
Jewel has been married too, and her 12-year-old son is from her marriage to pro cowboy, Ty Murray. They tied the knot in 2008 but split six years later.
In September, Kevin and Christine finally came to an agreement over their custody battle and divorce. They are parents to three teenagers: Cayden, 16; Hayes, 14; and Grace, 13.
The court ordered Kevin to pay a monthly child support of $63,209 to Christine, a much lower sum than the $248,000 she had originally requested. He also offered to pay $30,000 per month for a rental home after she vacated their estate.
Meanwhile, Christine was ordered to pay $14k of Kevin's divorce attorney fees.
A court judge also declared that the terms of their 2004 prenuptial agreement would be enforced which initially stated that Christine would receive a $1.5 million payout from Kevin should they divorce.
This came after the Dances With Wolves star's $80 million settlement with his ex-wife Cindy Silva.
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