Angelina if now both wear a belt and both hold each other's keys, this is taken to absurdity.
Doesn't have to be at the same time. For example... I'm currently stuck in chastity while my partner works away. He can't wear a cage on site, and there's not really much point given the surroundings (it's reeeeally remote). We video call most evenings, and he can open the key safe for me if he wants to. I don't care if he plays with himself when he's away.
When he comes home, we swap. I'm free for a week while he has to wear the cage (or belt, it's up to me). Sometimes I'll let him out to go surfing or whatever, but the way I see it he has obligations to his family, and I like being in control of that. Almost every interaction he's had with society this year he's had to do with a cage locked on his dick, and I think that's really hot.
Of course I tease him relentlessly, but the flipside is he gets to lock up his partner while he's out of town. It's romantic in and old fashioned knights & maidens kind of way. He knows I couldn't possibly cheat (not that I ever would) and I get to hold him by the balls. And we both have regular time off. Earlier this year we had a third party involved, and probably will again. It's the same situation, just stricter.