I think in this song, it's more that he spends his whole time waiting for her and worships the ground she walks on, but tries to pretend he's not that bothered. She is using him, and taking advantage of his position, getting into bed with him but never actually planning on leaving her husband. So he's left thinking about her all the time, knowing that she's using him but trying to pretend to himself that he isn't.
I think in this song, it's more that he spends his whole time waiting for her and worships the ground she walks on, but tries to pretend he's not that bothered. She is using him, and taking advantage of his position, getting into bed with him but never actually planning on leaving her husband. So he's left thinking about her all the time, knowing that she's using him but trying to pretend to himself that he isn't.
God - hope you understand all that! :S