CBT - Newbie

[Ruby]

For me, any turning of the purple (or blue), loss of blood or air to any area, I'd say only small amounts of time...in the less than 3 minutes. Nathaniel says 3 seconds. I prefer to play extra safe and usually avoid this type of bondage. And no, I'm not a doctor, just going with over the top caution to protect my partners and me.

Others offer this advice:

http://www.babeland.com/shoppingadvice/menstoysadvice/

and from one of my favorite sites:

"Masterbate for Peace"

http://www.masturbateforpeace.com/cock.html

When trying out this things, go with common sense and what works for you and your body.