Outdoor sex with sister

This happened when we were of school age. Once, my sister's friends arranged a trip to the forest, which was related to their studies. To reach that forest, we had to take a bus to the nearest harbor and then travel 20 minutes by boat. We arrived there by 11 am, and their boyfriends accompanied some of them. After completing study-related things, all persons had 2 hours of time for leisure activities. And my sister asked me to go into the forest. We both went almost 1km inside the forest from the point of all of us gathered. Then she took me under a huge tree and started kissing me. We enjoyed this a lot. And then she told me that she wants to do outdoor sex. At that time, I didn't know about that, but I said yes. Then she took off my t-shirt, and she removed her blouse. Then I kissed her lips, neck, and her boobs over the bra. I licked them. Then she removed her bra and asked me to suck them and spit on them. I did it. She was always watching around to confirm that nobody had seen us. Then she removed my trousers and smoothly licked and sucked my cock, which was so hard. Then she asked me to put my head inside her skirt, and I saw she didn't wear any knickers. Her pussy was so wet, and some of the juice came out, too. I licked all of them. She widened her legs, which made it easy to see her pussy lips, clit, and the hole. When she became crazier, she removed her skirt too. We were both fully nude in the forest for the first time. We rubbed our things with each other and enjoyed ourselves a lot. Then she asked to suck her pussy until she was satisfied. Yes, I did. After she was done, she asked me to wank on her boobs. That was the first outdoor sex experience for both of us.