“My Fair Wedding” reality-show host David Tutera announced last week that he and estranged partner Ryan Jurica would split their infant twins when in their custody agreement. The explanation is that each man is the biological father of only one of the twins. (They are “heteropaternal superfecundation,” or twins who share a mom but have different dads.) Jurica lives in Connecticut and Tutera lives in California. Jurica has said this is not the arrangement he hoped for, and he wants the twins to be in each other’s lives. Many experts, and people on social media, agree that this is a...