Brian wrote this towards the end of his marriage to Kerry, and after hearing Delta on the radio asked her to sing it with him as a duet. She was also having troubles in her relationship at the time and could relate to the lyrics.
So it seems to be about a relationship that Brian (in the song) had somewhat taken for granted, and now realising how unhappy his partner is (about him being emotionally unavailable perhaps?), he'd do anything for her to stay with him.
Brian wrote this towards the end of his marriage to Kerry, and after hearing Delta on the radio asked her to sing it with him as a duet. She was also having troubles in her relationship at the time and could relate to the lyrics. So it seems to be about a relationship that Brian (in the song) had somewhat taken for granted, and now realising how unhappy his partner is (about him being emotionally unavailable perhaps?), he'd do anything for her to stay with him.