Can I read my sons text messages through my iPhone?

Can I read my sons text messages through my iPhone?

No, give him some privacy, he'll hate you knowing that you don't trust him and are willing to look through his personal property to find out if your thoughts are correct. If you really suspect something, just ask him.

If it's imessage you can always connect your apple account to his iphone so you would receiveve all his messages and his replies.