It’s less about succumbing to hedonism, and more the fact that he was disobeying God (and trying to screw the women he was banging out of an inheritance).
He was supposed to impregnate his brothers widow to provide her with a son. This was a “levirate” marriage - essentially, the son would considered his brother’s and would inherit his brother’s property. Women didn’t inherit property, so this was a common practice to make sure that widows were taken care of.
Onan pulled out because he didn’t want to get her pregnant - he wanted the inheritance for himself. So he was being a massive douche, and deserved it.
It’s less about succumbing to hedonism, and more the fact that he was disobeying God (and trying to screw the women he was banging out of an inheritance).
He was supposed to impregnate his brothers widow to provide her with a son. This was a “levirate” marriage - essentially, the son would considered his brother’s and would inherit his brother’s property. Women didn’t inherit property, so this was a common practice to make sure that widows were taken care of.
Onan pulled out because he didn’t want to get her pregnant - he wanted the inheritance for himself. So he was being a massive douche, and deserved it.