My twin sister and I became closer than ever (PART 5)

For reminder, I'm M20 and she's F20. I previously said that we got into a heated verbal and physical fight concerning the morality of kissing as twin siblings. She took the upper hand and convinced me when she brought up my boner.

At this point I really thought we were doing the most illegal thing ever. Trust me I've loved my sister, I've had sexy dreams about her okay, but still when she put her jeans down and her thighs bounced off, it really made me think 'wtf am i doing, it's my sister'

She still had panties on, but when she turned, her ass looked so huge, it instantly gave me a boner. She saw it and without asking me, pulled my own pants down too. She said "Let's get comfortable, you can't learn with that itching in your pants"
She laid on me, her two thick thighs holding my boner, and she grabbed my throat and started licking my jaw. I really had no control over anything, she was owning me like her dog, and tbh i was scared because I didn't want her telling to our parents about the stuff I'm hiding?

I thought I was going insane like her if we end up having sex, but the whole thing became more smth like teacher/student. After licking me and giving me a boner on her thighs, she got on her back and told me to get on her. The obvious boner didn't let us close the gap so she took my dick with her long fingers and put it between her thighs, and it just got stuck there. SUCH A COLD WEIRD BUT GOOD FEELING! We ended up kissing from 3 to 4 hours, it wasn't awkward anymore, she was telling me plenty of techniques. We danced our tongues, sucked our tongues, played with our lips. And she really was being a really good sister. At the end she apologized for touching my dick earlier, she said I did good, and I should kiss her again tomorrow to see if I learned my lesson. I was kind of relieved she didn't make me do weird stuff. She also left her jeans in my room. So I covered my boner with her jeans and had a very long ejaculation makin the jean white

(Part 6 later)