Just look at me when I submitted to my master, who likes to see me struggle in bondage. He used a simple, but definitely escape-proof tool - an armbinder. My hands were tied so tightly I could barely move them. All I could do was wriggle on the bed, without any chance to escape. I tried for over 10 minutes - not possible! At the end, he just left the room, leaving me resigned on the bed...
