This past Sunday, Nick Jonas gave his girlfriend Olivia Culpo quite a shock when he walked off stage to serenade her during his performance of his hit song "Jealous."  According to E Online, the singer knelt towards the 22-year-old beauty queen, making her think he was proposing on live television.

Jonas told Yahoo Celebrity, "I went down and sang to her, and I [got] on a knee and approached her... Her face was in full panic. She thought I was going to propose on national TV in front of one billion people."

He didn't actually propose, but perhaps Culpo had good reason to suspect it. The couple has been dating since the summer of 2013, and Jonas has been rather public about the fact that Culpo inspired his song, "Jealous." She even appeared in its music video.

Culpo definitely has the ability to make Jonas jealous - he stated of the song, "I saw someone looking at her ass when we were out one night. It really upset me. The next day I went into the studio and wrote the song. So I got something good out of the experience even though in the moment it was frustrating."

However, Jonas is in no hurry to move quickly in his relationship. This past year, he said, "We're enjoying the ride together, and it's been a pretty insane year and a half... Lots of changes in both of our lives, and she's been a teammate through all of it. At some point, it would be ideal [to settle down], but we're still quite young and we're going on a journey."

Culpo has not responded publicly to Jonas' remarks about his Miss Universe performance, but she doesn't seem too fazed. E Online reports that she posted a photo of the two of them a day after the pageant, captioned, "Best part of tonight. Being serenaded by this stud."