Can they be dangerous? I am using the middle sized one, I think it is 1 1/2" in diameter. It fits on snug when I am flacid, and as I become erect it gets tighter, duh. However, once aroused everything starts bulging, the veins, etc. My penis also turns darker than normal. I think this is the purpose of the cock ring, but can one be too tight? When I cum with it on, It almost feels restricted and I get a little light headed. Is this ok? Or should I get a bigger one?