Kendall Jenner and Devin Booker were inseparable at her 818 Tequila party.
The 25-year-old model - who launched her own tequila brand earlier this year - was seen laughing and having fun with the NBA star during the rooftop party at the Sunset Beach Hotel on Shelter Island.
An eyewitness said: "They were laughing, playing around with each other and kept making eye contact throughout the night, and never stayed far away from each other."
Kendall Jenner com Devin Booker ontem no Sunset Beach. (18/08/2021) pic.twitter.com/t3rfbpsI3O
— KDBR Media (@KDBRmedia) August 19, 2021
Devin and Kendall's pals also seemed to be "very close and friendly" on the night.
Speaking to People, the source added: "At the end of the night, they walked out together hand in hand with nothing but smile."
📸 Kendall Jenner com amigos no Sunset Beach em Shelter Island Heights, Nova Iorque, ontem (18). pic.twitter.com/GpVNqLAJKG
— Kendall Brasil (@kendallsjbra) August 19, 2021
Devin recently returned home after winning a gold medal for Team USA at the Tokyo Olympics.
The basketball star helped his team to beat France at Saitama Super Arena in the men's basketball tournament, and Kendall subsequently posted a gold medal emoji on a picture of her TV, showing the sports star and his teammates celebrating on the court.
Prior to that, Kendall admitted she preferred to keep her relationship with the Phoenix Suns star out of the spotlight, particularly after seeing her elder sisters Kourtney, Kim and Khloe Kardashian go through "marriages and relationships and break-ups" publicly.
She said: "I feel like it's always worked better for me that way.
"No offence to my older sisters at all, but I think that Kylie [Jenner] and I specifically have had the opportunity to watch our older sisters go through marriages and relationships and break-ups and do them pretty publicly.
"It was personal preference from a really young age.
"I think it makes my life a lot easier and our relationship a lot better, to be honest ... I just feel like it's a private matter and not for anybody else to judge or know."