What happens when you separate the procreative from the unitive aspects of sex.

Artificial Insemination child still belongs to the husband. A couple has two children. The husband gets a vasectomy. The wife wants another child. She gets an anonymous sperm donor. The husband consents. Two years later they divorce. He tries to claim the child is not his so he has no responsibility for her. The judge says no: the kid is his. His consent, while omitting one of the legal forms, was sufficient.