i was wondering if tying my balls all night could make them blue and if if ithurts (and how much) and more important are there any permanent damages from this?
I heared cutting circulation is safe under 15 minutes. Maybe you could try step by step and check your body response but not sleep a night just to test. My advice is do not believe if someone states it is ok just do it.
If in doubt: don't - it's that simple - and if you don't know the answer, don't rely on answers from anonymous people on a kink forum. If you think you might want to have children in the future, you should probably postpone this particular kink ...