We've heard the phrase "affirmative consent" used in the context of sexual encounters, but what about the idea of affirmative consent for fatherhood? It seems in most legal jurisdictions, the man forfeits all rights in the case that the woman gets pregnant (for example, the woman can unilaterally opt out of motherhood by getting an abortion, but the man has no ability to opt out of fatherhood / child support). Wouldn't it be far more equitable if the man were able to provide affirmative non-consent (or consent, if he's actually interested in becoming a father) for fatherhood upfront, and be held liable, at most, for 50% of the medical cost of an abortion if an unwanted pregnancy occurs? In what world would that not be reasonable?