"They've been together now for several months, and while they've flown under the radar, it's quite serious," a source spilled about the budding Hollywood power couple. "She spends a lot of time at his place, and vice versa. It's not just some fling."
As OK! previously reported, the two shocked the world when they were caught smooching in the crowd of the star-studded September 4 concert after first being linked in April.
Despite being plagued by breakup rumors over the summer, Jenner was spotted days before their public date night at Chalamet's home on August 26.
"Timothée is a total gentleman and treats [Kylie] with respect," an insider said of the duo in the spring. "He's very charming and he makes her laugh, and he's easy to talk to."
- Kylie Jenner’s New Flame Timothée Chalamet Won’t Appear on 'The Kardashians' as Romance Takes Off: 'He’s a Private Guy'
- Kylie Jenner and Timothée Chalamet Caught Canoodling During First Public Date at Beyoncé Concert
- Kylie Jenner 'Open To Seeing Where Things Go' With 'Charming' Timothée Chalamet, Reveals Source: They Have Really Good Chemistry'
"He's not like any of the other guys she's dated before and although he may not seem like her type, they have really good chemistry," the source spilled of The Kardashians star's first romance after calling it quits with Travis Scott — with whom she shares children Stormi, 5, and son Aire, 1 — earlier this year.
Never miss a story — sign up for the OK! newsletter to stay up-to-date on the best of what OK! has to offer. It’s gossip too good to wait for!
People in the new couple's inner circle noted how the pair's mutual respect and laid-back attitude towards their separate lives has made their love go the distance. "He would never want to get in the way. He's sensitive and kind," the source said of Chamalet's understanding of her children being her top priority.
"They like to sit outside drinking a glass of wine together," the insider spilled. "Timothée is a calming influence on Kylie, and she's super impressed by his work. He's one of the youngest Best Actor Oscar nominees ever!"
InTouch spoke to sources close to Jenner and Chalamet.