Kylie Jenner and Timothée Chalamet Spotted Kissing at the US Open: See the Pics!

Nothing like a good game of tennis to turn up the heat for a new couple! Kylie Jenner and Timothee Chalamet were spotted packing on the PDA at the U.S. Open on Sunday.

The reality TV star and the Dune actor sat close together in the stands during the Men's Singles Final match between Novak Djokovic and Daniil Medvedev on day 14 of the sporting event at the USTA Billie Jean King National Tennis Center in Queens, New York.

Jenner, 26, and Chalamet, 27, sported dark looks, with the cosmetics mogul rocking a fitted black shirt and the Wonka star rocking a black hoodie over a charcoal gray t-shirt. Both wore dark shades to compliment the outfits.

During the heated match, the lovebirds were spotted with their arms around each other's shoulders, while Jenner would affectionately play with Chalamet's hair.

An eyewitness tells ET the two were "all over each other."

"They were in the private [Cadillac] suite. They made small talk with some of the other celebrity guests in the suite, but really, they just had eyes for each other -- and the match," says the eyewitness. "Kylie was drinking a Grey Goose Honey Deuce cocktail, which is the U.S. Open signature cocktail."

The eyewitness adds, "They really didn’t seem to care who saw them. They knew they were being photographed but that didn’t stop the PDA! They genuinely seem so happy and really into each other."

The pair even snuck in a quick kiss during the match -- which fans online pounced on in their analysis of the burgeoning couple's fun outing.

After months of romance rumors and speculation, Jenner and Chalamet were seen together last week at Beyoncé's Renaissance World Tour stop in Los Angeles -- and the pair didn't shy away from some steamy PDA during that outing either.

In what would be one of their first public events together, the rumored couple was spotted in a VIP section of the SoFi Stadium kissing with their arms around one another. In the videos shared by TMZ, the two stars were seen looking very intimate as they held each other close, lacing their fingers together while watching the show and turning to share a smooch here and there.

In another clip captured by Chris Gardner, a reporter for The Hollywood Reporter, the two are seen having an animated, flirty conversation alongside Kylie's older sister, Kendall Jenner.

Kylie and Timothée were first romantically linked in April when a source told ET that the two stars were enjoying each other's company.

"They are keeping things casual at this point," the source said at the time. "It's not serious, but Kylie is enjoying hanging out with Timothée and seeing where it goes. It's been really fun for her because it feels a lot different than her past relationships. It's new and exciting for Kylie and she's having a lot of fun."

Then in August, a source told ET, "Kylie and Timothée are still seeing each other when they can. Kylie’s busy with work and traveling a lot, but they make time for each other when it works and both like each other. They’re keeping things low-key and chill for now, but get along great and have fun together."

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