My twin sister and I became closer than ever (PART 15)

I'm M20 and she's F20, reminder: We sex-showered without actually having sex, she gave me her sluttiest face on a blowjob and told me she's having a girl over for sex tonight and that I must not disturb them

After the shower, she was in her bedroom almost all day. Half of me was craving to get even a sight of her giant melons in a tight top, but the other half of me became hateful of myself as I remembered "This is my own sister WTF". So I stayed in my room, read plenty of sibling-incest articles and it didn't make me feel better. Then I remembered I have a girlfriend, I took my phone, laid on my bed, and typed a loooong message to her: basically, I confessed to the crime of having intimate relations with my sister and I said how sorry I was. It didn't feel right to cheat on her like this bad. And I had to realize atp in time, my hearts belongs to my girlfriend but my lust and my dick ... well it belongs to my "female-twin"

It was a 4k word message. And guess what, after finishing it and reading it for mistakes, I decided to delete the whole thing and don't send her anything. A truth this brutal can knock someone out.

Bored asf as I was (and I wasn't horny), I opened my sister's bedroom only to scream in disgust. She was wearing a Guess bra, one titty out on her mouth. Her legs were opened fully, as she was using an electric dildo on her shaved pussy. "OH FUCK IM SORRY FUCK!"
She wasn't surprised, she kept going waving at me. I decided to step out but she told me to stay. She put her toy down, put her tit back in her bra, and sat up on the bed. I asked, "What the hell no keep going, I didn't mean to ..." and she gave me a sighed look, "I've been doing this for over an hour, I'm just bored, what's up?"

I sat up next to her shyly, and asked her what she meant when she said that we should practice, she giggled and said she's open to have her pussy fucked by me if it helps me gain experience.
"YOU'RE MY SIS!"
"THAT'S EVEN BETTER" she said back

(Part 16 later)