How disrespectful?

My boyfriend won't let me check his phone because he says we are not engaged. Everytime I take it, he won't give me the password. One time he gave it to me for a few seconds. Once he saw I was looking into his pictures, he grabbed his phone off my hands. I have asked him a billion of times to unlock his phone, he says he'll do it but he never does it.
Today, we were out for a coffee. I reached and took his phone, and he took mine. He managed to unlock my phone, while I didn't. I asked him to give back my phone but he wouldn't. I told him he doesn't let me see his phone, so I won't let him see mine. But he couldn't care less. He kept on checking through everything I had there despite me asking a billion of times to give it back. Then after some time he gave it to me. I was really angry with him, but he was laughing.

Before, we used to give to each other our phones. I would take his and he would let me, and vice versa. But one day he decided he wouldn't let me see his phone until we got engaged. So he stopped giving me the password!!! Sure he wouldn't stop me from taking it, but he wouldn't give me the password. When he asked for my phone, I would say I'd give it to him only if he gave it to me. But he never did!! So I wouldn't either give mine. And today this happened.
How disrespectful?
Post Opinion