Because blowjobs are awesome, that's why

You leaned forward a little and put a hand on the back of her head, not willing to let this moment be over just yet. "What do I say? I say, remember how blowjobs are your absolute favorite thing in the world and you just can't resist a cock in front of your mouth."

She gasped, her eyes returning to your cock instantly, and she dove forward again, her lips descending over your shaft even more eagerly than before. She moaned around you and closed her eyes, obviously loving it, and started to bob her , head; slowly for now, but with obvious enjoyment, making little contented sounds. You groaned too - you'd thought she was doing a good job before, but fuck, enthusiasm made one hell of a difference! Leaning back on your elbows, you just let her go at it for a little while. Not much like getting your dick sucked to help a guy relax a little, you thought.

After a few minutes, you figured it was time to vary things up a little bit. You gently pulled Slutbunny - wait, Serena? Eh, whatever, you were pretty sure she'd respond to either by now - off your cock, and she whimpered a little, her tongue extending to try and get a lick. She looked up at you pleadingly, not sure what was going on. You smiled down at her. "No worries, you can get back to it in a second. Let's hop up on the bed."

She obeyed with gusto, obviously glad to do whatever she had to do to get your cock back in her mouth. You felt yourself get even harder watching her do so, knowing you'd put that intense desire into her mind. You shifted further onto the bed yourself, letting her crawl between your legs as you propped a couple pillows behind your head so you could look down at her comfortably. She opened her mouth gleefully, but you held her back for just a second with her lips just barely on the tip, wanting to flex your power a little and see how deep this memory-twisting stuff went while you were at it. "Would you rather lose your ability to speak, but get the perfect mouth for giving blowjobs, or stop sucking my cock right now and get the body you've always dreamed of?"