There seems to be a rather common misconception out there that chastity devices are designed or intended to prevent erections. I don’t understand why this way of thinking is still around. If you get a cock cage that actually fits properly, there isn’t any trouble with that. You can get hard frequently; you just can’t orgasm. The point of chastity is to prevent orgasm, not erections. Why is this so hard for some people to grasp? It’s called “orgasm control” for a reason.
If you’re locked up, and it hurts when you get hard, there’s something wrong. Most likely, your cage is too small or you’re using the wrong size ring. Having a secure fit doesn’t mean it should strangle all the blood out of your cock.
Besides, why would you want to prevent your sub from getting hard? Why would you condition someone to stay flaccid all the time? Hard cocks are sexy. Just because he’s hard doesn’t mean you have to let him orgasm. Do you want to condition him to not have other normal biological functions as well?
It’s sort of like saying that underwear is designed to squeeze your balls until you wince. If you buy them three sizes too small, then yes, they’ll do that. But if you buy the right size, they fit well and function normally. Cock cages are no different.
Chastity has nothing to do with suppressing sex drive or erections. In fact, it’s just the opposite. It’s about driving someone crazy, it’s about power, it’s about control, it’s about ownership. All very sexy things.