While originally implied to be homosexuality, it can be just as easily broadened further, due to the vague open ended lyrics, to include pretty much anything in which the person "sinned", but in that the "sin" in question is referring not to an actual "sin", so much as just not conforming to social expectations at the time.
Anything which is taboo, goes against cultural social norms, and so on, would fit just as snugly into the "sin" that's phrased here.
While originally implied to be homosexuality, it can be just as easily broadened further, due to the vague open ended lyrics, to include pretty much anything in which the person "sinned", but in that the "sin" in question is referring not to an actual "sin", so much as just not conforming to social expectations at the time.
Anything which is taboo, goes against cultural social norms, and so on, would fit just as snugly into the "sin" that's phrased here.