Help please

Tatiana • ; Mother to a handsome boy and a beautiful baby girl ❤️
My fiancé and I came to Denver on vacation for a pre wedding honeymoon and my honey wanted to smoke. And a few minutes ago he got very angry because I asked my my ex who is a big ole pot head what's the best out there. No he wants to go thru all of our previous messages. 
From 2012- April 2015. 
Does he have the right to do so.? Was I wrong for asking my ex?
My fiancé and I have only been together since May 2015