We Drank, We Fucked

My sister was flying out on holiday with her friends on Sunday, So she came down Friday to be close to the airport and do some last minute shopping. She did shopping on Friday afternoon and then we met up at the pub to have a couple of drinks. We had a really fun time as we meet very happy people that night and a couple of drinks turned into a night out. We were already really drunk by the time we took a taxi back to my flat. When got in the flat we decided to have a final drink and put some music on to dance. One drink then two drinks and so on. We were dancing really flirtatious which turned me on and guess she noticed as i was rubbing her ass. We ended in one of those situations that show me yours and I'll show you mine. I was actually quite surprised i was hard considering all the drink. I went to the room and she went to the bathroom because we decided to get naked and at the count of 10 we would both get out to the living room. We did 1, 2, 3......10 and we jumped out and ran to the living room. A couple more drinks and more dancing teasing me to get it down. But as fate would have it in one of those ass shaking moments my dick slid in as she was quite wet. I couldn't help my self and grabbed here waist and started thrusting my dick in and out of her wet pussy. She turned her head around and she had that face of being mad, but she just said, we tell no one of this. Then she got down and started sucking my dick. We did everything that night, nothing beats a drunk sex marathon. We only stoped to smoke some weed and drink some more. I took a secret male enhancer Which kept me hard all night. We had sex on the sofa, on the floor, in the kitchen, room, bathroom, well everywhere we could. She gushed everywhere and i must have cumed 5 times on her tits, on here back and also inside her. When the sun started coming out we went to the bedroom had a final fuck and fell asleep. Next afternoon When we woke up naked with a banging headache and hungry we looked at each other and the only thing she said, That was a crazy night. We walked into the living room to asses the damage and for sure there was cum and wet all over the place. I went to the kitchen to prepare us a tea and while the kettle was boiling she came around hugged me and grabbed my cock. As my cock started to get hard again she turned me around and said Fuck me. We spent that afternoon watching marvel movies and fucking one another. That night she prepared her bag and we went to bed early, we had quite intimate sex and fell asleep. Next morning 4 am she wakes me up saying taxi is waiting for her. We said our goodbyes and she also said we tell no one.
I spent the day thinking of what we have done, racking my brain around the situation. Morally ethically, What if, was it a one of... anyway all i can think of is how good it was. She called when she arrived at that hotel and that and girls are settled, and said maybe when we get back I could visit you more often and that she really had fun and enjoyed it. All is said sure anytime.