You can delete Instagram messages in two different ways – by deleting an entire conversation or by "unsending" a message.

The good news is if you do something similar you can delete the accidental message, ideally before it’s seen by its unintentional recipient. To delete a message, just press and hold on the ...

If you've sent an unfortunate DM on Instagram, here's how to delete a message. Plus, deleting your comments and unsending an unread message.