The Yellowstone star, 68, was on the island for a tennis fundraiser for Jewel s Inspiring Children Foundation. TMZ reported the arrived together, were flirty, then left together.
The 49-year-old singer used to be wed to cowboy Ty Murray, which is interesting as Costner is best known for playing a cowboy on Yellowstone. She was also with Sean and a football star.
The 49-year-old singer appears to be in the best shape of her life as she posed in swimwear. She had on a black one piece suit that revealed a flawless and svelte shape.