Kendall Jenner's relationship with Devin Booker has "gotten more serious"

A source explained: "She felt ready to share a bit more than she has in the past when she posted the photo of them on Valentine's Day."

The brunette beauty - who has previously dated the likes of Blake Griffin and Ben Simmons - is said to feel "comfortable and safe" around the 24-year-old sports star.

The insider explained to 'Entertainment Tonight': "Their relationship has gotten more serious and Devin is really laid back and not all about fame or being in the spotlight all the time, which Kendall really likes.

"He makes her feel comfortable and safe and he's super respectful, which are all qualities she loves."

Previously, a source close to the situation claimed their romance didn't require any "crazy commitments on either side".

The sports star was also understanding about Kendall's hectic work schedule.

The insider said: "There aren’t any huge expectations or crazy commitments on either side. They have gotten a lot closer, but Kendall’s schedule is particularly super busy and Devin is very understanding of that."

Meanwhile, Kendall previously described herself as a "love-at-first-sight type of person".

She explained: "I am very much someone who, I am a love-at-first-sight type of person. I know I am gonna fall in love with you the second that I meet you."

The model also thinks she's a "really straightforward person".

She reflected: "I have this overwhelming feeling. And that doesn’t happen a lot for me. I am not the kind of person who can gradually fall in love with someone. I don’t understand that. I’m a really straightforward person."