Bondage and marriage go well together because despite what the photos LOOK like, it is about trust. To answer your question boringly, adding another depends upon the trust level.
Occasionally my wife and I get into bondage; both of us taking turns in the restraints, and it is fun. There is no greater surprise, no greater reward than figuring out how to tie myself to the bed X-fashion and having her come in and see my present for her: me!