the labours of Heracles

in describing how Zeus made love with Alcmene(he took her husband's form and then you know), he noted that
Similar to a well-known episode in Arthurian legend, Merlin disguises Uther Pendragon as Gorlois, husband of Igraine, and in that form he sleeps with her and fathers Arthur..
Well, that truly astonished me.
And then, from Perseus to Heracles, the former was famous for slew Medusa and the other, was the child of Perseus's granddaughter, but, here's an other note he made, yet Zeus made love to Perseus's mother with the form of showered gold, and Zeus again, made love to Heracles's mother with the form of her husband, so, naturally, Perseus was Heracles's Great grandfather, and his half brother too.
Oh god.