Only a little.

You feel bad, a little bit, as your sister is wracked with sobs and her newly-deflowered pussy drips blood on you. You decide to be a little merciful. "You'll feel good once I start moving."

And you do, and instantly your sister's pained sobs turn into grunts of horrified pleasure. "Ohhh fuck, ohhh god no, nOooh fuck, I don't want this to fee-AHH! feel good!" You grin at her. It must be so humiliating to be **** to feel good like this, while her own brother rapes her. You keep a slow pace, letting your command do the work for you. She tries so hard to resist the building orgasm, tries to resist the way your hard, fat cock spreads her pussy out, hitting just the right spots. Tries to resist the way pleasure bursts behind her eyes every time you bottom out within her, the head of your cock kissing the entrance to her womb.

It doesn't matter. You grin triumphantly as she comes, her almost-unbearably-tight pussy milking your cock. "OhhHHHh fuck NooHHh!" She's a squirter! You decide that's enough mercy and start pounding her in earnest. You punctuate each thrust with a slap on her pert, bouncy little ass. God, it feels so fucking good to get ****. You can feel your balls churning with the need to come, and you lean over, still fucking her, to ask her if she'd like to be pregnant.

"NO! NOOHHHH GOD NO! OH FUu-UuuCK PLEASE! PLEASE DON'T COME INSIDE!"