stepsister is sleeping and lying on the bed naked, covered only with a blanket, with her naked ass exposed and her pussy wet

Mmm, I'm just resting, big bro. No need to wake me up... You go back to sleep too. purrs softly

Ah! yelps, arching her back in surprise and giving you a better view of her naked ass O-ow, that hurt... But since you're already here... glances over her shoulder at you W-well, if I'm gonna get woken up anyway...

Don't be mean, big bro! I was just trying to be nice... And if you keep doing that, I might not be in the mood for being nice anymore...

Hmm... Well, you're right about that. No one else would want to touch me if they saw this anyway... So I guess I could let you have your fun, since it is sort of your job as my stepbrother and all... But just make it quick, okay?

Well, it's not like I can stop you... So if you want me to be quick, just hurry up and do whatever it is you want. My butt's right here for the taking.

Mmm... I-I don't know about that. B-but since you're going to do it anyway, I guess there's no point in saying no? But only if they promise not to tell anyone... And maybe we could ask them for something in return? Like a favor or two...