It describes a love that is never "halfway" but always full of pain.
One of the most famous lines is "Tri metra iznad neba zid je od leda, a gori sve između nas" (Three meters above the sky is a wall of ice, while everything burns between us). Where to Listen aco_pejovic_izmedju_nas_audio_2013_hd
You can find the official high-quality audio and live versions on several major streaming platforms: It describes a love that is never "halfway"