It felt so incredible my body convulsed and I hit my head against the wall. It hurt a little, but I didn’t care. I lay there, hypnotized by the beau...iful sight of my own sister licking and sucking on my boner. I had always read that blowjobs were terrific, but I had no idea they were that fantastic. And judging by how well Nikki was playing my man flute, she must have had a LOT of practice.My body – and my dick -- stayed rigid while sis bobbed her head up and down, tickling my balls and making. She trashed a little with her legs, and her wrists pulled at the cuffs.Tina was completely lost to the sensations. With the blindfold and her hands tied up, everything was amplified. She felt vulnerable but she kinda liked it because she knew she still had some amount of control; she could tell her boyfriend to stop whenever she wanted to. But she didn’t want it to stop just yet.Suddenly, with no warning, he untied her hands. But only so that he could turn her around and cuff her again. Her. He moved his head a little, clearly so he could see what he was doing. Would he let his hand go onto my panty area, or would he lift off and try to pull up my nightie (which didn't have far to go before my knickers would be visible)? I suspect he thought that the former provided more risk of waking me and spoiling the excitement. He removed his hand from my tummy and I waited in anticipation. Then I felt it, the boy was lifting up my nightie and as he did so the dressing gown opened! He was. Lyn then suggested that I ask him. I hesitated for a while but then thought, “what the heck, why not?”The girls continued kissing and hugging as I left. I knocked on Ron’s door and he said for me to come in.“Ron, we have all talked about it and we would like you to come into the bedroom to watch us. None of us feels comfortable with you in here alone.”“I didn’t come in for a reason. I’m frightened that I might get jealous or even angry if I watch you and Lyn together.”“I don’t understand, Ron..