Like you could say no to that.

You'd been looking forward to Kelly rescinding her earlier rejection, you'd intended to milk her humiliation at having to eat her own words for all it was worth. Seeing her there now, desperately but sweetly looking up at you as her hands fiddled with your zipper, you knew you couldn't do that. She'd laid herself bare to you so profoundly that, even though you already had full control over her, she'd made herself utterly ****. It touched you in some bizarre, sibling/lover way that you really weren't expecting.

Feeling your urge to taunt her slip through your fingers, you sigh exasperatedly, "Well I can't say no to that... with your stupid puppydog eyes and mushy feminine whiles."

You continue to grumble as Kelly smiles widely, freeing your cock in mere moments and showering it in hurried kisses, "Mwah, thank you, thank you, thank y-mmph!" before sheathing you in her mouth. She meets your surprised stare with a lustful one of her own as she goes to town on your cock. She was just full of surprises today, those kisses were totally her own thing, you never told her to show you any affection. Not for the first time, though certainly the strongest so far, you feel a powerful surge of guilt over what you'd done to Kelly.

After a few moments of back and forth you rationalize that you never would have seen this side of "sisterly love" if you hadn't used the ring, so really you were just improving your sibling relationship. It makes you feel like an even worse scumbag and you resolve to treat her better from here on out.

Not that you were going to try and change her back or anything. That would just be crazy.

Your encounters with Kelly become so frequent and regular that it becomes a part of your schedule: wake up to morning blowjob/assfuck from your sister, go to school, give her a discreet fondle during lunch so she could make it through the day, then pound her ass one to two times before bed sometime later. It was an exciting, and exhausting, enough cycle that you barely have the time or energy to pursue Mom. Which makes her little goodnight kisses all the more enjoyable.

She was just as hesitant the first few times, and she never looked 'comfortable' walking into your room wearing straight-up seduction material, but thanks to your time on the couch (you think) her compelled kisses are met with a lot less horror from her. You actually have time to slip her the tongue back on the third try. She didn't take it well and you had to spend a few minutes calming her down, which you're pleased to admit you didn't have to use the ring for.

In fact, you'd been pretty mellow with the ring after your initial barrage of commands and improbable dick portal-ing. This new life suited you, venting all your sexual urges with your hot sister and enjoying a budding (romance?) relationship with your mother.