And Onan knew that the seed should not be his; and it came to pass, when he went in unto his brother's wife, that he spilled it on the ground, lest that he should give seed to his brother.
Every Sperm is Sacred
I understand Catholics use Onan for lessons against jacking off but that misses the bigger point of the story. Onan dishonored the family and disobeyed God. I do agree life is sacred.