Sexual encounters with sister

Hi, I am only 9 months or so ahead of my sister in terms of age, she is dirty blonde, blue eyes, nice ass, and great legs, and wears short pants often. I want to see her naked as well but she closes her door when she changes and showers and in bed she is under covers, I feel like that would be a good start but I don’t know how to do that. We have had sexual encounters when we were younger, the earliest account I remember was when we were maybe **, and we shared a bedroom and I guess it was due to experimentation I cant figure out any other reason, at this time I have been jerking off for a year or two, anyways, my brother’s friend was coming over and we were going to have hot dogs and for some reason I went upstairs with sister and asked if she wanted to masturbate and she said yes, so I stared when I was sitting on a suitcase in the closed closet and she got out of the closet and laughed and said she was going to tell mom and she did luckily she just brushed it off, then things between me and my sister started getting hot because, I started to eat her pussy around the same age as the last one, I remember she asked me to lick her pussy and of course me being young and a guy I said yes and I ate her out a lot and everywhere, I even ate her out behind my brother when he was playing, we did it for a while and then I wanted to stick my dick in her. We “did it for a while but we didn’t actually despite me thinking we were fucking I would always asked if it was in but it was really just rubbing against her pussy, we stopped and then we moved, and at the new house I saw her and her gorgeous ass in these tight purple white dotted boxer panties that sat high up on her and showed her ass greatly, this was around the time I started to wear boxer. At this time we still didn’t close doors while showering so then we could either pour cold water on each other or just to peak on them in the shower. At this time for a while we bathed together but out of fun, we had games we played like coffee shop were all we did was put water and soap into a cup and then serve it that’s it, but I liked it, it was fun and I got to see her nude. Now skip ahead to where we were bathing together and we weren’t really sexual at least I cant remember if we were, anyway, we took a bath in our parents bathroom and this was the first time she saw my dick in a while, we were playing coffee shop a little bit and I got a hard on and tried to hide it under the cup in my hand and she said I should move it because she wanted to see it, and I said okay, she wanted me to jerk off and I said I would if she would too we both did, I started to get really horny and asked if I could stick it in again, and me being young I couldn’t find her hole so I just asked if I could stick it in her butt. I put the tip in and she screamed and put a towel on and ran away, thankfully she didn’t tell my parents. Nothing much happened in the time we were at the house so skip ahead to where I was looking through my parents closet and I found this box at the top of their closet and I opened it and there were vibrators, like a big one, and a small pill type one, there was vaginal lube, and sex dice, and a condom. I didn’t tell anyone for a few days until my sister and I were alone. I showed her the box and she got really turned on instantly as soon as she turned on the vibrator, she said kiss me so we started making out on our parents bed, she even started to dry hump me until my parents came home she shot off of me and played it off like nothing had happened. Fast forward to the most recent event.. we were going to watch a movie when we started to have a pillow fight, I kept making remarks saying I’ll suck your juices out, she said okay go ahead and pulled her pants down and showed me her pink pussy I started to eat her out for while until I heard someone coming up the stairs and we quickly stopped and played a movie. Thankfully we did because my dad came in saying to keep it down he was going to sleep. Nothing has happened since.