If you turn on disappearing messages, their Signal client will delete the messages unless they turn it off again. And of course they'll always be able to take a

If you turn on disappearing messages, their Signal client will delete the messages unless they turn it off again. And of course they'll always be able to take a screenshot of your message before it disappears - it does not work if your conversation partner is your adversary. But if you care about messages disappearing and your partner doesn't mind, you can set them to disappear and they will disappear from both your devices.