Well, the singer's being in a bar DOES have something to do with the state of the relationship in question, and I think we (the audience) are supposed to take that under consideration, whether or not the singer (i.e., the character he represents) is fully conscious.

I really don't think we're supposed to believe that the singer just happened to see a male person at the woman's house, and that he might be misinterpreting an entirely innocent and coincidental meeting. No, he's calling her and knows the guy is there even though he's elsewhere and can't see, because the guy is always there, or at least has been most evenings lately.

Which came first ~ the man's exile to a barroom, or the woman's taking up with another? Could be either way, which in turn would gtell us which partner is more to blame for thye break. Of course, it's almost always true that both share in the culpability.