PS: The chorus is is, of course, asking them why they are there, in that relationship, in that place. "Only the lonely resent angels for flyin'" is saying that, if they truly loved each other, and weren't simply clinging to each other because of fear and inertia, they could let the other go, without resenting the fact that they're leaving. And in fact, could be happy to see someone they love actually living, even if it didn't involve them.
PS: The chorus is is, of course, asking them why they are there, in that relationship, in that place. "Only the lonely resent angels for flyin'" is saying that, if they truly loved each other, and weren't simply clinging to each other because of fear and inertia, they could let the other go, without resenting the fact that they're leaving. And in fact, could be happy to see someone they love actually living, even if it didn't involve them.