The two have literally been through thick and thin ever since Camp Rock, but now, seemingly out nowhere, Demi has unfollowed Nick off Instagram.
It comes at a time that Demi has admittedly relapsed from her sobriety after six long years... and fans are starting to wonder if it's the fact that Nick's relationship with new girlfriend Priyanka Chopra is heating up fast.
You may remember when Demi released her song "Ruin The Friendship" that she basically admitted to wanting to take the next step with him (or so fans assumed).
But since, they have remained just friends.
Nick was also there for Demi through her past struggles, which he touched on in her documentary Simply Complicated.
“I felt a bit of pride about it,” he said. “Selfishly, maybe I thought I’m helping her come back to being the Demi we all know and love.”
Hopefully whatever Demi is going through right now, Nick will still be there for her.