In the black and white photo, Gomez, 21, is cradling the 20-year-old singer's head in her arms and gazing into the camera, reported Us magazine.
Bieber momentarily captioned the pic, "Our love is unconditional."
This is not the first time the Justin Bieber, 20, has randomly shown love for Selena Gomez on Instagram.
Back in March, the 'Boyfriend' hitmaker posted a picture of Gomez at the Vanity Fair after-party in West Hollywood, with the caption: "Most elegant princess in the world."
Bieber and the 'Come & Get It' songstress were last spotted together at Coachella in April.