Open Relationship Prevalence, Characteristics, and Correlates in a Nationally Representative Sample of Canadian Adults
Nevertheless, buried away in it are a few interesting tidbits that the authors downplayed. For example:
(about one-quarter), of those in CNM [open] relationships would nevertheless prefer to be in a monogamous relationship.
the highest [satisfaction] group (those in monogamous relationships whose preferred relationship type was monogamous).
I also thought this was interesting:
In a large-scale (N = 2,270) representative sample of U.S. adults (Levine et al., 2018), 39.7% of gay men and lesbians and 34.5% of bisexual men and women reported being in a CNM/open relationship compared with 10.1% of straight participants.
I have the full study. And here's a screenshot of a related tweet: