A vague post aimed at one person is a conversation you were too nervous to have directly.

Posting it sideways gets the feeling out without the risk of their reply, which is why it is tempting. It also guarantees the wrong outcome: they either miss it or see it and learn that you would rather perform than speak. Whatever you needed to say is still unsaid afterward. The nerve it took to post was almost enough for the conversation.

If you have one of these drafted, send it to the person as a message instead, short and without the audience. If that is too much, say nothing for now and come back to it. Either beats a post that only works if they are watching.