Why does the article's title say this is "counter-intuitive"? If anything, it seems completely intuitive to me; promiscuous people, regardless of sex, are most likely to cheat and not want to stay married.
I can only assume it's because of the "have fun first, settle down later" mindset many people tend to have with regards to sex and relationships. I agree, though, it's not a great title.
Because 2018 sexual dogma is quite firm on the position that "N count" is entirely irrelevant when selecting a partner and that you are either a pig, a slut-shamer, or a misogynist bigot for even inquiring.
Any evidence that "N count" is, in fact, relevant would be regarded by modern sociologists as counterintuitive.