Rethinking monogamy today
A decade or so out, the "experts" will be back, telling us how men in these relationshits seem to invest less effort into the (inevitable) children that aren't biologically theirs.... consensual non-monogamy can be a healthy option for some couples and, executed thoughtfully, can inject relationships with some much-needed novelty and excitement.
As a couples sex therapist, I've found that some may feel committed to each other yet still feel they have fundamental differences in sexual interests or desires. In the past, many of these couples might have chosen to break up, cheat or just "settle."
For now, if you don't want into the cultural petri dish, you're a "pathetic weasel".