ET's Lauren Zima caught up with the cute couple at the Race to Erase MS Gala at the Beverly Hilton in Los Angeles on Friday, where they opened up about a possible proposal after Hilton arrived with a ring on that finger.
"This is actually a gift from my friend, Rosalina," Hilton explained, before her beau added that the pair are "not yet" engaged.
"You'll find out," Zylka teased.
"[We're] soulmates, for sure," Hilton gushed. "100 percent."
"You wake up with a smile and you fall asleep with a smile," Zylka said of life with his ladylove.
"[Being soulmates is] just being best friends and finally finding someone that I love and trust and know that I want to spend the rest of my life with," the former reality star added. "It's the best feeling in the world."
Hilton isn't the only one head over heels for Zylka. According to the blonde beauty, the 31-year-old Leftovers star already has mom Kathy Hilton's approval.
"My mom loves him. She definitely approves!" she revealed. "She's so happy. She already says he's part of the family."
Hilton and Zylka didn't just come out for date night. Hilton has been a long supporter of Race to Erase MS as her grandmother died of the disease.
"Losing my grandmother to MS was so painful and I love that [the organization's founder] Nancy [Davis] really puts so much work and effort into this event every year," she explained. "They're finding cures and really making a huge difference, so I always want to be here and support her every single year."
In between supporting important charities, the 36-year-old heiress has been focusing on her business, though says she gets "offers every single day" to return to reality TV.
"We were actually watching [The Simple Life] two nights ago and just laughing! It's just so fun and timeless. I had the best time doing it," she confessed. "I feel like I was the pioneer in that, and had an amazing time, but now I'm focusing on more important things like my business."
Hilton's relationship with Zylka has also become a priority, however.