Alternately, Papa- and Mama-Oriax.
This is my d&d player's character's parents. Simon the Incubus, and Dahlia the human.
Their backstory is, simply put that Dahlia was seduced by the Incubus, and was banished to Shadowfell when the local wizard found out she'd been messing around with a fiend. Their son was born and raised in Shadowfell, but he traveled to the Material Plane to find a way to get his mother back there too.
I take no credit for the backstory, it's my player who made that up.
The fullsize image can be viewed in my dA Scraps: https://sta.sh/0298mg0moduk