I think this is about lust and the emotional pain/unhappyness linked to it.
I don't know if this is the real meaning of this line, but "Bringer of light" is the translation of Lucifer in Latin - meaning this lady is a bitch but being "All dressed in white", she looks amazing which makes the narrator want her (LUST).
"I started to cry after hours of joyful sin" - the crying shows emotional pain, JOYFUL sin = sex which he obviously enjoyed.
I think this is about lust and the emotional pain/unhappyness linked to it. I don't know if this is the real meaning of this line, but "Bringer of light" is the translation of Lucifer in Latin - meaning this lady is a bitch but being "All dressed in white", she looks amazing which makes the narrator want her (LUST). "I started to cry after hours of joyful sin" - the crying shows emotional pain, JOYFUL sin = sex which he obviously enjoyed.