My thought is that this song is about guilt and anger. The guy is a bit confused and ambivalent about the relationship at first (he used to be fine with being alone), but now it's amounting to something more in his heart. He could have met her randomly and they became romantically involved, but she is either in another relationship or feels guilty about the experience they shared (classic 'he doesn't meet my social standards' response). Now she sneaks away to him, feeling guilty, but enjoying his company. He was fine with this casual side-relationship at first, but now he's beginning to care and be a bit angry about it, maybe wishing it had never begun because he knows things can only go downhill from this point.
My thought is that this song is about guilt and anger. The guy is a bit confused and ambivalent about the relationship at first (he used to be fine with being alone), but now it's amounting to something more in his heart. He could have met her randomly and they became romantically involved, but she is either in another relationship or feels guilty about the experience they shared (classic 'he doesn't meet my social standards' response). Now she sneaks away to him, feeling guilty, but enjoying his company. He was fine with this casual side-relationship at first, but now he's beginning to care and be a bit angry about it, maybe wishing it had never begun because he knows things can only go downhill from this point.