anyone who picks at every little thing a partner or potential partner does by requiring the Internet to approve it is toxic as hell. asking the Internet if a behavior that doesn't effect you is a red flag is a massive red flag.
i mean, it's more about letting the Internet decide for them. a person that is so incapable of making their own assessments that they have to ask a random mob permission to date another isn't going to be a good person to date. didn't be or date someone that would trust random Internet weirdos who collectively have an incredibly awful track record of giving advice over just talking about it or doing some reading.