You are Alain, a daring and plucky adventurer.
One day, while exploring a long-forgotten tomb to some ancient empire, you uncovered a strange ring. Daring and reckless as you are, you put it on. When you did, a succubus appeared in a flash of light. She was tall and slender, with bountiful breasts and wide hips. Flowing locks of pale golden hair framed her delicate face and glowing purple eyes. If it weren't for her horns and wings, she'd look almost like a beautiful maiden. No stranger to the tricks of a succubus, you struck her down—or, at least, you would have, but your blade passed right through her.
The succubus, introducing herself as Annabael, insisted on following you around, constantly petitioning you to allow her to perform lewd acts on you.
Eventually, you found a sage, who was able to inform you on the nature of the ring you found. It is a cursed ring—those that put it on will be followed by a lustful succubus. She cannot harm you, and you cannot harm her. Only one way to break the curse is known—have sex with the succubus. However, this would allow her to drain your energy and end your life.
"I reject that, old man!" you defiantly shout at the sage. "I'll find my own way to break the curse."
"No you won't," smirks Annabael.
The sage sighs, and says "Well, all curses can be broken, but the nature of this one has been lost to the ages. You may have to search for a long, long time to break the curse."
"Or," Annabael says, "you could let me fuck you!"
"No," you respond indignantly.
"Just the tip," she pleads.
"Not on your life," you reply.
"Not even a little lick?" she begs.
"No way, fiend," you boast.
Annabael sighs, and says "Well, we could at least get out of this dusty hovel."
"That's right," you beam. "I'm going to find a cure for this curse!"
The sage puts his tomes away and says "I wish you good luck, Alain."
"You'll need it, he-ro," Annabael intones.
You step out of the sage's hovel and into the wilderness, with your persistent succubus in tow.