A shared childhood gives adults a language that spouses may need time to understand.

Brothers and sisters carry a compressed vocabulary: half sentences, a tone that means one particular Christmas, a name standing in for a whole year. It is not exclusive by design and it is impenetrable in practice, and someone who married in can spend a decade in the room without the references opening. The intimacy is real and so is the exclusion, and mostly nobody intends the second.

If a partner is with you around your family, unpack one reference for them as it happens. And if you are the one outside it, asking what a joke means is not an interruption, it is how you get let in.