Of course its been known to happen not quite so often in humans, for a person to have male genes from 2 different fathers but again thats like a friggin rarety. Usually its from double partner to a double egg ovulation which couldve caused twins but for some reason the 2nd twin didnt make it but fused in a way with the 1st twin. Ive only heard of this happening once in my lifetime but who knows how rare or often it actually happens. Its usually found out when said person is sick and test are done.