It seems that users will get a free pass on the first time, where they will be prompted by a popup that lets them know that the “next time” they take a screenshot or even a screen recording of a Story, that person will know that they’ve done it. We suppose it is fair to let people know when their content has been saved, although we’re also sure that there are some who would prefer if their screenshotting habits are about to become a bit more public.
That being said, there are some ways to go about this if you’d rather not have the person know. It has been pointed out by users that putting your phone in airplane mode (thus cutting off all connections) will let you take screenshots without the other user knowing, although it can be troublesome and you might forget.
An alternative is that you can take screenshots on your computer via the Instagram website, or use a third-party app like Story Reposter. That being said, recently it was revealed that Instagram is testing out a new feature that lets you repost somebody else’s post onto your Story.