You're not sure.

You know what it seems like; the erotic thoughts, the heavy and slow panting, the fact that your erection is probably the hardest you've ever had, and that if you weren't driving(at a much reduced speed you note), you'd probably have pulled it out and started working it right there. You risk a glance beside you. Melissa's in a similar boat; she's panting the same, her left hand is slowly massaging her breast through the t-shirt, and the right has disappeared beneath her skirt. Her eyes, almost pleading, are looking right into yours. The sight of that breaks the flimsy resistance you have, and you are soon showing your full length to her as you slowly stroke it.

Doing so has caused you to let go of the wheel of the truck, but you hardly notice that it is still
going straight and still slowing. You are far more interested in the show beside you.

Melissa has apparently had enough of her shirt, as she quickly removes it and throws it into the back. She sighs, half pleased and half concerned, as she begins groping her breast at a rougher pace. Her right hand has also begun a faster pace, and has hiked up her skirt enough to give you a better look. Your jeans have pooled to your ankles as you are working a faster pace as well. You both also scoot closer together in the seat. You look at her eyes, seeing the confusion and lust building in the- wait, are they faintly glowing red? The raised eyebrows of your passenger informs you that the same must be in yours. Wait, when did you get infected? Did a little semen get on her at her house?

Where did this fog come from?

You turn(with more than a little effort) your gaze ahead. Sure enough, you've come to a complete stop, and the fog surrounding you has cut off the sun. In the distance, you think you can make out a shape, and you can tell by the wings that it isn't human. You feel something on your wrist, and look back to your side.

Melissa has scooted next to you(or possibly you both have scooted the gap between you two away), and has moved her right hand up to her breasts. Her left has grabbed your wrist and you watch as she guides your hand to her bare mound, your fingers already probing her depths before you can even think about her action. She let goes of your wrist and moves her free hand to your cock, stroking it with surprising skill. Once more, your eyes meet, and you see the glow has brightened considerably.

"Ah-hem."

You both look ahead, and judging from Melissa's stroking speeding up, you both are sharing the same thoughts. Outside is perhaps the most inhumanly beautiful succubus you've ever seen. Just one glance is making you want to either fuck her or the nearest person in her name.

"It seems you two are so eager already, so I won't ask. Just start already and I'll tell you what's
going to happen."