I always thought it was someone speaking from the point of view as the person who both people in a relationship go to in order to feel like they are on the right side of an argument, the deliberator or a moderator between two people who's relationship is failing. Thus he is the person who is alone and tired of hearing about the possibility from either person about being alone, they don't notice he already is and he finds that inconsiderate.
I might be reaching too far but that's what I got out of it.
I always thought it was someone speaking from the point of view as the person who both people in a relationship go to in order to feel like they are on the right side of an argument, the deliberator or a moderator between two people who's relationship is failing. Thus he is the person who is alone and tired of hearing about the possibility from either person about being alone, they don't notice he already is and he finds that inconsiderate.
I might be reaching too far but that's what I got out of it.