He brought the 23-year-old onstage during an appearance in Burbank, California, and promptly serenaded Jordin before the assembled crowd as the two lovebirds shared a kiss with one another.
A delighted Jordin - who wore a T-shirt reading: 'I fancy the lead singer' - gushed and smiled as her guy got down on one knee at one point much to the amusement of the crowd.
My girl! Jason Derulo serenades his girlfriend Jordin Sparks in Burbank on Friday
With her hair tied back and wearing tight black spandex leggings, a black vest and pink baseball boots, Jordin was in a playful mood as she flirted with her guy.
Jason, 23, showed off his muscular physique in a red vest with black pants and baseball boots as he had a lot of fun wooing his lady.
I like him too! Jordin wears a T-Shirt reading: I Fancy The Lead Singer as she joined Jason on stage
Packing on the PDA: Jason then pulled Jordin in for a passionate kiss in front of the delighted crowd
Jason is trying to carve out a singing career for himself and released his first single The Other Side back in April.
The Miami-born artist and the Idol winner have been dating for over a year and they are obviously madly in love.
So in love: Jordin looked smitten as she stood with her arms around her man
'When The Other Side comes on, I get this big, cheesy grin on my face,' she said.
'I know he was thinking about me when he wrote it. We love being able to support each other in what we do.'
Strong opinion: Jordin let everyone know who she was thinking about
Back in January, the Sparkle actress told Glamour magazine: 'Marriage doesn’t scare us, but we’re not in a rush either.'
And Jason recently confessed that Jordin has been so enthusiastic she's started sending him pictures of engagement rings.
'It’ll happen when the time is right,' he told Ryan Seacrest on his radio show.
Dance with me: Jordin and Jason did some moves together for their fans