Hot Summer Job/Start talking to Bree about sex
You let out a small sigh and begin to rub Bree's little butt-cheeks, to “comfort” her considering how upset she just got at your recent conversation. Your stroking hand gently brushes against the shaft of your cock and your tight ball-sack, triggering them to grow and strain inside of her in anticipation of what is on your mind. It is an amazing feeling. You already shot a load of cum inside her, but your dick hasn't gone down at all. In fact, it is all ready for more. You have never encountered this while masturbating. Seems like real sex is a lot better, and now you can't wait to do it some more with your apparently “safe” and presumably willing sister.
“W... well then,” you say far less confidently than you had intended to come off in your head. “I guess this means we can have sex now.” You look back up to Bree with a hopeful smile. Her sour face turns to a look of confusion as she rears back a little and meets you in the eyes.
“What's that?” She asks.
Wait, what is sex? Shouldn't she have had sex ed in her classes by now? You are pretty sure, you heard your mother talking about how they were going to be talking about sex in Bree's class a couple months ago, they were going to be reading a book about it designed for fourth graders. They didn't have that when you were in elementary school, maybe they didn't explain it to them very well? Or was Bree goofing off in class and not paying attention? Maybe she just needs you to jog her memory.