I'm all for diversity, but this should include "boring" couples who were high school sweethearts, got married and, somehow, despite everything, are still happy together.
Or not. Fine. Break them apart, but don't transform them into other people...
If other couples want to be poliamorous, sure, go ahead. Write them this way. I think it's distasteful for Scott and Jean. Can you imagine how the conversation went between them when they realised they were mutants and monogamy was too passé for them?
- Scott: We can't stop thinking about other people, right?
- Jean: Yeah. Let's stop fighting it?
- Scott: Okay. But family is still important, right?
- Jean: Sure. I can cook dinner, I guess.
- Scott: Open marriage, then?
- Jean: Calling ourselves husband and wife is still important even though that is a human *ugh* institution?
- Scott: Yes. You know me. I'm very consertive.
- Jean: All right, then.