The way I hear the song, it sounds like one of two similar situations. (1) she is having an affair with her boyfriend's best friend or brother (2) they are both married and having an affair -- either way she is tired of the lie and ready to expose the secret or leave him. In the end she seemingly does leave him thus removing his choice/need for them to meet in a veil of secrecy and lies.
The way I hear the song, it sounds like one of two similar situations. (1) she is having an affair with her boyfriend's best friend or brother (2) they are both married and having an affair -- either way she is tired of the lie and ready to expose the secret or leave him. In the end she seemingly does leave him thus removing his choice/need for them to meet in a veil of secrecy and lies.