My twin sister and I became closer than ever (PART 6)

For reminder, I'm M20 and she's F20. I previously said that after arguing, she convinced me to do more kissing. She held my cock, and left her jeans in my room.

I woke up to remember I had the best day ever, but the guilt returned. I got caught with quite a headache thinking that I'm doing incest kissing with my sister. As I was searching for her jeans (that I made it dirty), I realized it wasn't there anymore. She might have came back during my sleep to take it back. I figured I need to speak to her again, that we should stop. I headed out to my bedroom, opened her bedroom only to find her wearing the same jeans I was masturbating on. I was still, I couldn't speak or say that "we should stop", instead she came up to me with a smile and brought her face to mine and told me, "Pretend I'm your girlfriend. I'm not doing the kissing, you are."

Without a question, I took my tongue inside of her mouth, danced with her teeth and lips, it lasted only a few minutes. When I stopped, she told me "You're ready." I asked 'How do you know?". She simply replied with a little blush "You got me wet."
I blushed too, looked down, and indeed her jeans were getting wet on her thighs area. I got out of her room awkwardly, and she closed the door awkwardly, she just reminded me "Don't touch her ass when you start. If she kisses with her tongue back, then firmly hold her ass, she will love it." I just nodded.

In fact, today was the day. I've gone to a few dates already with my gf, and i'm planning to kiss my gf on her lips. Date happened, we were on the grass, I got up on her, she got a bit scared and asked if I've kissed anybody before. I lied that I never did and we're both unexperienced. I put my tongue into her mouth, I did exactly what my sister did to me and after some good ten minutes, my gf stopped me, "There's no way you didn't kiss anybody, you're an expert!"

Really glad she loved it, we did more kissing, she didn't mind the ass-holding too.

(Part 7 later)