You can't deny her, but she has more conditions...

You sit there sheepishly. Looking at her cock in your hand. It's just as hard as yours was. It's longer, thicker, but just as tempting. You think back to any of the times you could have stopped. You could have walked away. You could have read the manual. You could be in her position! But here you are, giving in. You can't resist her. You can no longer resist what the ring has done to you. You can't stop now. She has you like marionette.

"Yes" you say, regretfully. You don't want to let it continue. But it's just sitting there, you can't resist it.

"Well first things first." She pulls the ring off her cock. Just as quickly as you were devouring it, it disappears. "From here forward you are drinking from the source directly. Second go get your phone. We'll continue when you get back." She says pointing to the door. Her cock still hard as she puts the ring on but doesn't have it port anywhere. You try to respond but she just emphasizes her point. You go back to your room, grab your phone and hurry back to her room shutting the door behind you.

"Happy?" You say impatiently tossing the phone on the bed.

"Yes, unlock it for me and then you can continue your meal. And I want more than head this time." You head over to her bed, grab your phone, unlock it and hand it to her. Once there is an unimpeded line between you and your addiction you make a b-line and dive on it.taking the head in your sister moans. She begins digging through your phone. What she could be digging for is the last thought on your mind as you enter a haze, the pre-cum clouding your mind. Your cock has begun to harden as the haze begins to form. Moving a hand down you begin to stroke your member. You begin to take her down, you get about half way down before it hits your throat. You stop as you know you couldn't deep throat this. Not without any practice. It's not like before today you had a history of sucking cock.

"Oooooooo, well lookie here. What drove you to do this?" She says showing you the selfie you took. Your cock half in frame, mouth full of cum. "Well I can take a guess." She says placing a finger on the ring. You keep diving as much as your throat will allow. She is intoxicating. Her cock is covered in pre and your saliva. Drunk on taste you could keep this up forever. She begins to tense up, you know this feeling. You begin to feel it as well. She begins to breath heavily.

"I'm gonna cum, take it and don't spill a drop!" She shouts as she explodes down your throat. The hot stream tingles your throat in ways your semen didn't. Maybe it was because it was someone else. Your mind is nothing but pure ecstasy as you cum yourself. Spraying all over her sheets your hips bucking back and forth. Laying on the sheets you collapse. Your stomach covered in your own semen. After a few minutes you and your sister come back to reality from the bliss you both indulged in.

"Oh, well. I am happy to keep going. Wait. Did you blow your load all over my bed!?! What the fuck John! If you weren't already in deep shit. You're about to be." She pushes you back. Sitting her self higher up looking at your phone still. "Oooh, and I just found one way to solve that problem."