She tells

I heard Claire going in front and each saying hello. “What are you doing out at this hour?”
“Nothing much. Just relaxing outside.” She lowered her voice but I was still able to make out “But I think there’s a naked guy on the side of the house.” Shit I was in trouble.
I looked around but the hedge was too thick to go through, especially naked. So I just stood there naked with my hand over my cock. The first to appear was Victoria.
She was still very cute. She was a bit taller than Claire and more athletic. She was wearing a very small red tube top and black short. She had much smaller breast than Claire (big A or small B) but was more free to show her body. She often wear skimpy outfit like the one she was wearing that showed a lot of skin. She had blond hair like her sister but she kept it very short. She would always wear very small bikini and her bottom was always in the thong format. When I was younger, I would always come out to see her ass if I heard a splash. I think she knew because she would tease me a lot and then, in the end, show it to me. Every time, I was rock hard by the time she finished.
Of course seeing her now, with not a lot of clothes, brought back memories and my cock started to get hard under my hand. First, appeared outrage on Victoria’s face, then surprise as she recognized me. “What are doing? Are you spying on my sister naked?”
“No!” My brain froze a bit that I realized that I live just next door. “And if I wanted too, why would I do it here instead of in my backyard where the chance I would have and escape route?”
That made her pause. “Well maybe.” She stopped to think and her eyes started wandering all over me. A small smile appeared on her face. “You turned out great. Do you remember when you use to look at me when I was in the pool?” I think my face turned red because she added: “Humm, you do remember and you liked that. Ok now it’s my turn. Turn around, I want to see your ass.” I was shocked by her request and Claire was also surprised. “Come on, I want to see if your ass as cute as the rest of you.”
I was even more turn on. I turned around showing my ass. “Could you put on hands on your head? I always liked what that does to the back and ass.” I was sure I really affected my ass but I complied. After a bit of silence Victoria continued: “Hmm, it’s really nice but I want to see the front again.” I turned back again but left my hands behind my head. I was now fully exposed and my cock was pointing strait at them from the excitement I felt showing off two girls who, from the looks in their eyes, seemed to enjoyed watching. “Hmmm, I think we can have some fun. If you follow me, I’ll make sure you get a nice reward.” She licked her lips and glanced toward my cock. “Come on Claire, let’s see how much fun we can have with him.” And she left, with Claire just behind her after one last glanced at me.