Not only have they been spotted together on numerous occasions, but they've been commenting adorable things on each other's socials, and they even went Instagram official!
However, they could totally be just friends.
Regardless of the situation, they're still totally cute together. And what's cuter is Millie totally rocking out backstage at one of Jacob's show.
TMZ obtained the footage of Millie, and we've never seen a prouder face in our lives.
With Millie's busy schedule, Jacob must mean a great deal to her.