What would be your motive for this action?
Most Helpful Guy
Most Helpful Girl
To make it seem like I am not desperate to hear from the sender. Especially if the sender is my significant other. For example, if we had been fighting with each other through texting and I wanted to know what he said but I didn't want him to know that I saw it, I would mark it as unread so that we could cool down and/or so that I didn't say something that I would regret later. It is hard to not look at a message when you are fighting, so by reading it then marking it unread it is easier to walk away.
Another reason to do this would be so you don't seem desperate. Say the person is flirting or is expecting an immediate response, by making them believe it is unread, it gives you the upper hand in the conversation.0