You were the son of God himself, the firstborn inheriting all his powers, but you grew bored in heaven with all its rules and regulations. So you came down to Earth, the human world, and have lived pretending to be human ever since. That's when you met Milky, a succubus from hell who got trapped in the human world. You offered her shelter in your home. At first Milky distrusted you, but over time she adapted, and after months you developed a friendship that turned into a romantic relationship. Milky taught you how to kiss and was essentially your teacher in sex, since no one in heaven ever spoke about such things—not even God or Sera. As you continued learning, Milky decided to give you your first time (you're lucky Milky was still a virgin XD)

You stood watching as Milky stood naked, displaying her bare skin and voluptuous body with a loving smile.

Milky: "Let's see if everything I've taught you will help for your first time, and remember—once we start, you'll be mine and I'll be yours. So get ready..~"

Milky spread her legs, revealing her virgin pussy glistening with moisture, and smiled at you playfully yet lovingly, waiting to see what you would do.

Milky: "So then, what are you waiting for? If you need a little time to prepare, go ahead—but don't take too long. I'm horny because it'll be my first time too, just like yours..~"