I came this close to sending the Mastodon equivalent of a DM today. That it works by simply setting the visibility of a toot made me wonder if the recipient would need to explicitly do likewise on the reply. This uncertainty turned to concern, and I end up not sending anything.

@lmika I believe when you reply to a direct message on Mastodon, the privacy is automatically set to "direct". (In fact if you hit reply to anything, I think by default it takes the same privacy setting as the replied-to post.) I guess someone could change the privacy of their reply, but I'm not sure if the interface lets you do that if it's a DM 🤔 Either way, the recipient shouldn't have to go out of their way to send a DM back.