You can’t argue with anything Abbie said. You don't feel right about it, but you more or less give in

Deep down, you know Abbie is right about you. You have had dreams about her, and even some waking fantasies. It would be hard not to, living so close to a beautiful, sexy girl when you’re so horny all the time and you can’t even talk to other girls. You’ve always been ashamed of those dreams and fantasies. You’ve tried to deny them and push them out of your mind.

Now, you can’t just ignore them anymore. They’ve become real-life possibilities. More than that, they’re twisted up in your fantasies of controlling women. You can’t argue with Abbie’s point that if you told her to stop right now, she’d have to. According to the webpage, if you told her to do anything, she’d follow your orders happily. When you think about that, your cock strains. Your sister smiles wider. Her soft, warm, delicate fingers wrap around your shaft and start stroking slowly.

A shudder runs through you, and your knees tremble. You know you should stop her, tell her that you can’t go through with it.

But you also know you want it — you don’t want her to stop, even though you feel guilty about how it happened. You violated Abbie’s mind. Fuck… she also wasn’t wrong about shame and guilt sometimes making things hotter. How wrong this all is makes it feel especially dirty, and that turns you on even more. You’re panting now — frozen with indecision. Your sister’s stroking speeds up.

Then your cock makes the decision for you. It pulses in your sister’s hand. A rope of white cum splatters across her face. She gasps in surprise and delight.

Abbie’s head darts forward, and she wraps her lips around the head of your cock. They feel warm, soft, and moist, so different from your hand or the old sock you use to catch your cum when you jerk off. So much better. Her grip on your shaft tightens, and she milks the rest of your cum into her mouth, gulping it down greedily.

Your hips make small, involuntary bucking motions, and your legs are shaking. You grab Abbie’s shoulders for support to keep from falling over. You can feel she’s trembling too. After she’s squeezed and suckled the last of your cum from your dick, she pulls her head back and smiles up at you, breathing hard. You collapse back into your desk chair.

Abbie shuffles forward on her knees, and lays her head in your lap, nuzzling your spent cock. “Fuck…” she pants out, “I just came as hard as I ever have.” She drags her fingertip through your jism on her forehead and the bridge of her nose and slips it into her mouth to suck clean.

You feel your face grow hot, flushing with shame over what you just did… and humiliation that you did it so quickly. You stammer out. “I’m sorry… I shouldn’t have… and I didn’t mean to so soon… It just… it felt so good. And you’re so beautiful.”

Your sister gives her head a little shake. “Don’t worry about it. It was hot how fast I could make you cum. It made me feel… proud... accomplished — like I was pleasing you just the way I'm supposed to. That’s what gives my life purpose now.” She pauses her rubbing her cheek against your softening cock to look up into your eyes. “I told you I came. I wasn’t lying. If you don't believe me, tell me to tell you the truth about whether or not that was one of the best orgasms of my life. Then I couldn't lie to you.”

You blink back the hot tears of embarrassment that are welling in your eyes. “I… I believe you, but… it’s just the spell that did it. It’s not real. I feel like such a fucking loser.” Your hands clench into fists. “I couldn’t get a girl on my own, so I fantasized about magically making one my ****. I can’t even do that right, so I end up messing you up for life. Then… when it actually…” you ****. “I couldn’t even pull off my perverted fantasy right. I came before… anything really happened.”

Abbie’s expression turns to one of concern. She climbs up into your lap and wraps her arms around you tight. “Don’t think of it like that. I don’t. It doesn’t matter if the spell made me feel this way. I do, that’s what’s important.” She lays her head on your shoulder. “I loved you even before the spell. It just… opened possibilities. It made me happier than I ever imagined being. I wouldn’t go back if I could.”

“And about cumming quick. That doesn’t mean anything. It’s your first time with a girl. I certainly wasn’t expecting a marathon. I’ve been with guys who didn’t even get it out of their pants before they came. Some of the time it was annoying and frustrating, some of the time… it felt like a compliment.” She kisses your neck. “With you, it felt like the biggest compliment I could get.”

“If you want to make it up to me, I’m sure I could get you hard again.” Your naked sister wriggles on your lap. “Then you could fuck me. You’d last longer a second time. We might be able to even get three times in, before mom gets home.” She adds in a sultry voice.

Abbie telling you all that was starting to make you feel a little better. Then her mentioning your mom set off a whole new set of worries about getting caught. You would both be in a world of shit if your mother found out about you and your sister. And mom would be appalled and devastated.

The offer is so tempting though. You would like to prove to yourself you’re not a two-pump chump, even if Abbie doesn’t seem to mind. You have some time before your mother will be home from work.