There are also scenarios where A & B are both seeing other Alphabet characters outside of their dynamic:
A has a relationship with LMN
B may only have a relationship with Z
Z may be involved with W who happens to not be kinky/a foodie/ a person who likes travels so W is totally fine with Z finding U and doing those things with them.
Poly relationships are as different as the people involved the key is transparency.
PS
I meant to say dimensional not dementianal in post 62 I can't fucking correct it on my damn iPhone so sorry for the misspelling