Actually attempting an orgasm while wearing a lock

We’re kind of the opposite of many people. I live with my wife and my long-time kink partner, who has an apartment downstairs. My wife unlocks me for sex, but doesnt like me to orgasm during or after. When I do stuff with my kink (she’s the bottom) partner (she lives with us) I have to stay locked up. What we are looking for is a way for me to release now and then that doesnt involve me masturbating. That pretty much leaves trying to orgasm or at least ejaculate while locked. I can occasionally orgasm through pain/nipple play and we are thinking to experiment with prostate massage. The tricky part there is that I have Crohns disease and cant really have a finger inserted. Has anyone had luck with external prostate massage?