So far, I haven't seen much discussion about what you and your spouse are comfortable with or not comfortable with. I would be curious to see a post about what you've discussed between the two of you, and what has come up.
In my opinion, your rules should be about preventing things that would make one or both of you feel uncomfortable. Period. You've heard some of the common rules (condoms, get permission), and some of the less common ones. What do you and your SO think of some of these?