To me this song is sort of a contrast to all those stereotypical songs about feeling unloved or wanting love from someone. It shows how cold and melancholy it is to be on the otherside, to be in a relationship but know you don't feel anything for the partner and are just waiting for the right time to end it.
By saying that she can't help if they're 'going abroad' shows that she doesn't want to commit. But she'll carry on pretending to seemingly prolong the hurt she'll cause, 'ill call you baby i will and i do'.