I think it’s such a harbinger of doom! ‘We need to talk’ or ‘have you got time for a chat later about something’, or ‘I’ll explain later what it’s about…’
And no further detail, even when you say, go on, tell me! Be it to a friend, in the workplace, your other half, your sibling… honestly just say what you’ve got to say, or don’t bother requesting to talk until the time you actually want to talk. Why cause anxiety in folk for the sake of it? My mind immediately goes 100mph wondering what it could be. I’ve always hated when people do this. Am I the only one??