Basically Morgana's parents Gorlois and Vivienne died so Uther, Arthur's dad took her in when she was 10 because Gorlois was his best friend. Arthur and Morgana grew up like siblings but later in the show we find out that Uther slept with his best friends wife Vivienne and had a child which was Morgana. So they grew up like siblings but found out later they were actually half siblings (same dad different moms). Arthur's mom died while giving birth to him btw
He said “social call” lol
Basically Morgana's parents Gorlois and Vivienne died so Uther, Arthur's dad took her in when she was 10 because Gorlois was his best friend. Arthur and Morgana grew up like siblings but later in the show we find out that Uther slept with his best friends wife Vivienne and had a child which was Morgana. So they grew up like siblings but found out later they were actually half siblings (same dad different moms). Arthur's mom died while giving birth to him btw
Damn makes sense now