True open relationships are different in kind from “I don’t give a fuck what you do on your own time” relationships. The former are verbally confirmed agreements to strange and psychologically toxic sexual and romantic arrangements that defy biosocial realities and are often designed to the benefit of weird lesser beta females and their ovulation cycles, and to the detriment of lesser beta males with scarcity mentalities and low T; the latter are emergent conditions of the player lifestyle where quantity of experience is valued higher than quality of experience, and short term trysts are valued higher than long term commitments.
I’ve known more than a few dyed in the wool cads who genuinely did not give two fucks (or pretended very convincingly not to give two fucks) about what their flings were doing out of sight. But these cads weren’t getting on bended knee for their lovers either. If that sort of commitment expectation was on the table, and they were considering it, then you can bet they’d drop their pretense of giving no fucks about the sexual fidelity of their girlfriends, (even if they themselves continued giving no fucks about their own caddish infidelity).