"That moment when..." Jonas, 23, captioned the photo along with a smiling face with sunglasses emoji.
While the singers have been friends for years, it's clear most of their fans would be on board if their relationship took a romantic turn.
Fans flooded the comment section writing, "Ya'll look hot together," and "You guys look so cute together" along with tons of smiling face with heart-shaped eyes emojis.
The photo appears to be pretty recent as it was taken at this year's Billboard Music Awards, which was held on May 22.
The Last Year Was Complicated hit maker revealed he's happily single at the moment on Tuesday's episode of Watch What Happens Live. "I'm meeting people and hanging out, I'm not in a relationship," he told host Andy Cohen.
Jonas was last linked to actress Kate Hudson following his two-year relationship with Olivia Culpo.
Cabello, 19, was previously linked to singer Shawn Mendes and dated Austin Mahone for nearly a year.