Lots of communication and expectations that match each others. A little bit of acknowledgement on the boards and maybe just a tint touch of possessiveness but exclusivity doesn’t have to be a hard line unless it’s what all parties want and need.
Oh, and complementary kinks would be nice
No, not all.
But I do think it should be much more socially acceptable and talked about more. In my opinion, it could/would solve some of the issues that come with the pressures of monogamous marriages by taking the pressure off one person and one person only being responsible for someone else’s pleasure