The 23-year-old California-based rapper took to Instagram on Tuesday, spilling his heart out to the 26-year-old American Idol season six winner.
"Can't sit here and act industry like this s**t don't hurt me," Sage wrote. "You the only girl I can call at 3 in the morning and you'll answer no problem. You the only girl that can wake up out of a dead sleep and get me some water because I was coughing in my sleep, the only girl that loves me the way you were supposed to. I miss you too much to watch you look so amazing at the Clive Davis party and not be able to call you and express how much I appreciated the look because you won't answer nor text back. The feeling is horrible."
Sage's message accompanied a picture of himself with Sparks in happier times.
"You see this picture?" he continued. "That's the picture of me lookin at n****s lookin at you and givin them the eye like 'wassup n***a' and you like it's ok babe and you makin me smile and feel just a little more secure about it."
Sage ended his message by assuring Sparks that he's "still being a good boy" just in case she ever comes around and pleads with her to return his calls.
"I just want like a hug and a kiss or something," he wrote.
Sage later tweeted a new song called "I'll Keep Loving You."
"So I say it in a song," he wrote.
Last year, the couple couldn't have been more in love. In May, Sparks revealed her nickname for Sage was Baemaxx, as in bae to the max, which was inspired by a character in Disney's Big Hero 6 called Baymax.
In July, Sparks told ET that Sage called her "wife."
The two were first linked in April 2015, following Sparks' split from Jason Derulo.