Falling into a rabbit hole of Greek mythology on Wikipedia one night (I'm not very knowledgeable on the subject), I stumbled across a genealogy tree that lists King Minos as a distant descendent of Zeus and Lo which made me think of something regarding Storm's father's lineage. The story of that pairing involved Lo getting turned into a heifer. Given the odd workings of Greek god genetics and curses, what if that experience left an impression on Lo's genes and passed down to future generations, including King Minos? Thus also being passed down through Minos' children and their descendants. This includes Strom's paternal parent, whether he was a human or a person who also was the seven son (etc) and had the bull gene expressed and was using a passport to pass as human when he had a one night stand with Storm's mother. It might make a connection to between Asterion and Storm if Storm was a descendant of one of Asterion's half siblings.
Though a more similar explanation could also be that Asterion had sex with a woman at some point, maybe even a previous master, and had a human looking child and Storm lost the cosmic lottery with his situation.