I'm not entirely sure what you're trying to say here. That idols don't necessarily date, but are more likely to be promiscuous instead? Because that would be one loaded assumption.
Also, adults don't necessarily have active sex lives just because they're adults (and unfortunately, the reverse is also true for children.)
having sex doesn't mean one is promiscuous. Im saying that dating is pretty looks down upon so while idols might be worried about committing to being officially partners, they might instead prefer nothing or casual relationships. At least at the start of their careers