Been trying to remember if there's an episode of a podcast I listen to that dealt with this (the modern mann, named for the host, it's not male-focused, there's a segment where Alix Fox talks about sex-related questions), and I think there's a couple that are related but not precisely.
Communication is definitely one of the things I know have been brought up as very important. Setting expectations and boundaries.
This may be one of those topics I think you might have to browse reddit to get a lot of experienced/detailed answers for - /r/EthicalNonMonogamy would be the place to search, probably.
I have never met a lactose intolerant person that didnt, upon mentioning it when they inevitably buy something full of lactose, look me dead in the eye and confirm their terrible intolerance before going into a frightening lactose-consuming frenzy that chilled me to my very core.
They know the price they must pay. They laugh at death and spit in the face of genetics. A grim, dangerous people, the lactose intolerant.