@SatoshiRyuusei
Spoiler!
Zechs has an adopted brother, Orca. Everyone forgets Orca is male, including Zechs and probably even Orca himself because they're just so effeminate. I haven't picked up the story since the main arc ended so I don't know if Orca gets pregnant but Zechs is basically a G** at the end of the story so impregnating another man seems entirely possible. Honestly, I just put Orca being male out of my head the entire time because it's also only infrequently mentioned and usually when someone calls Orca a woman to which Orca will correct them. Orca's basically a girl in appearance and personality.