Say you were immortal and witnessed a supernova from a million light-years away. Eventually, after another million years have passed, you meet another immortal

Say you were immortal and witnessed a supernova from a million light-years away. Eventually, after another million years have passed, you meet another immortal who happened to be right next to the supernova when it happened. When talking to this other immortal, would you refer to the event as happening two million years ago (when you witnessed it), or three million years ago (when the other immortal witnessed it)?