Nah, the Onan crime thing is about Levantine Marriage. Basically if your brother dies you're supposed to marry his wife and have kids, and legally those kids are your brothers kids so his bloodline keeps going. It's a really important cultural thing. Onan's crime as that he was banging his brother's wife without knocking her up, so he was basically committing a crime against his brother and his family that was really serious in the culture of the time. Had nothing to do with masturbating.

Basicalyl Onan was being a shit because he didn't want to take on teh burden of raising his brothers kids. Seriously, has absolutely nothing what so ever to do with masturbating or pulling out or anything else.