A source tells ET that the couple has talked about marriage, but are taking their relationship one step at a time.
The superstar couple may not be into flaunting PDA in public -- or even walking the red carpet together -- but that doesn't mean they're any less committed to each other. In fact, a source tells ET that they are more devoted than ever.
"Kylie and Travis have been inseparable lately, and their love for Stormi just seems to bring them closer every day,” ET's source says. According to the source, Kylie and Travis, who welcomed daughter Stormi together in February, have talked about getting married, but it's important to them to take things one step at a time.
"When Kris [Jenner] sees Kylie and Travis together, she's convinced they're on the right path,” the source shares. “At first she worried about Kylie starting a family so young because she felt she had no say. Kris knows Kylie does what Kylie wants, so Kris just had to hope for the best.”
Kylie's sisters have also given Travis their stamp of approval. "Kim, Khloe and Kourtney are pleasantly surprised by how involved Travis has become in his daughter's life. They know he has a huge career, but he is clearly taking the time to be there for both Kylie and Stormi,” the source notes.
Travis has definitely proven his devotion to Kylie, and so has she. See all the ways they've shown they're in it for the long haul below.
They're Completely Inseparable
Two busy careers means Kylie and Travis take complete advantage of the time they're together. The pair has been inseparable over the past week, as they traveled together to New York City for the 2018 MTV Video Music Awards.
Kylie and Travis didn't pose together on the red carpet, but they were by each other's side during the show -- and in the days that followed. The couple was snapped by photographers sharing a sweet kiss in the city, and took to Instagram to reveal that Stormi is still their No. 1 priority with precious new family photos.
They Make a Big Deal Out of Birthdays
Every birthday is a milestone in the Jenner-Scott household, and each one deserves to be celebrated in a big way. When Travis turned 26 in May, Kylie rented out Six Flags Magic Mountain in Valencia, California, so they could have the park to themselves for a party with friends and family. She even ordered him a custom cake of the two of them -- plus baby Stormi -- riding a roller coaster. Just days later, they took the party to a tropical beach, where they enjoyed a little getaway with their baby girl.
In their recent GQ cover story, Kylie opened up about the most romantic thing Travis has ever done for her, and admitted it occurred during her 20th birthday last year.
"On my birthday, he woke me up out of bed at like six in the morning," she recalled. "He was like, 'We gotta go,' and I'm just like half asleep, like, 'What do you mean? What do you mean?' And he just starts pulling me, and the sun was just coming up, and he had flowers all the way down his house and violin players everywhere."
For her 21st birthday, Kylie went all out with a star-studded bash in Los Angeles, and received a white vintage Rolls-Royce from her boyfriend. "Happy bday wifey I love u mommy u my heart rib toes and all. May GOD continue to bless u and ur spirit. This mark in ur life is the start to more greatness," he wrote in a sweet birthday tribute to Kylie, before the two were spotted jewelry shopping, presumably for something special.
"Travis surprised Kylie with an incredible vintage Rolls-Royce and thousands of flowers while the two were having a romantic dinner at home," a source told ET at the time, before the two jetted off to Las Vegas to keep the party going.
Nicknames Have Real Meaning
Travis referred to Kylie as his "wifey" in his Instagram post, and according a source, while the two aren't married, it was just another sign of their devotion to each other. "It was just a term of endearment," the source said, noting the two "are madly in love."
The couple also has a collection of nicknames for their daughter, Stormi. "Storm Storm," "Burrito," "Peanut" and -- in an apparent reference to Game of Thrones' Khaleesi -- "Stormborn" are just a few of the adorable pet names for their little girl, as they revealed in a sweet video for GQ.
She Supports His Career
Kylie has supported her man from the beginning. As they noted in their GQ feature, they met at the Coachella Valley Music and Arts Festival in Indio, California, and she joined him on tour to keep exploring their romance.
She continued to accompany him on the road even after Stormi was born, traveling with him to Europe this summer while he performed in France. She couldn't stop gushing over her man on social media while supporting his new album, Astroworld, and even stripped down to star in his new music video for "Stop Trying to Be God."
"You didn’t have to go this hard baby ? Astroworld just dropped and it’s the craziest ride of my life ???," Kylie wrote on Instagram when Travis released his new album. Last week, she revealed that she and Stormi will be joining him on his Astroworld tour.
The twosome are all about Astroworld -- so much so that Nicki Minaj called Travis out for having Kylie promote his new album. But so far, the pair haven't been paying the drama any mind.
... And He Supports Hers
Travis was on board with Kylie Cosmetics even before Forbes magazine put his girlfriend on their cover of their America’s Richest Self-Made Women issue last month for her nearly billion-dollar brand. In March, he joked his "new part-time job" was helping Kylie test out her makeup, as he shared videos to his Instagram Stories of the pair testing out swatches.
The rapper also makes compromises when it comes to their personal lives. He admitted in GQ that he "hates restaurants," but just days later, he was spotted enjoying a dinner date with Kylie.
But They're Not in It for the Fame
Kylie and Travis have kept their relationship private from the beginning, from their first date to her pregnancy with Stormi, to their current all-in romance.
As Kylie explained in GQ, having that sense of privacy allows them to really focus on each other. “Like, if we were in L.A., I feel like it would've been way different. Everything happened for a reason," she said of their whirlwind first meeting at Coachella and her spontaneously choosing to join him on the road. "We weren't going out as ‘Kylie and Trav.’ We would just be in Cleveland, walking the street for hours. We would go on walks, and no one would bother us.”
“That's why we just go the extra mile to keep our relationship super private, or like, if he has events or something, I won't come," she continued. "Because I want him to do his own thing. I want him to be him. I don't want it to be Kylie and Trav. If people don't ever see us together, that's OK with me, because we just do our thing.”
See more on Kylie and Travis in the video below.
Reporting by Adriane Schwartz.