"We’re not really sure." Sirius rolled their shoulders back and stretched their neck from side to side, showing off their exposed broad chest and defined collar bones. "By all accounts we should be short, sickly humans with huge jaws and no sperm. Instead, we’re both tall, hardy, and handsome. And I can’t speak for Reg, but I have no shortage of sperm. The only explanation I can think of is that the Blacks made a deal with the devil."