3 years ago, Snapchat caused some problems in my relationship and I deleted it (a guy friend was being disrespectful of my relationship when I clearly told him I was not interested, I had set my account to private, but then thought that deleting it altogether was best), because it's not worth having issues over. Come to find out my boyfriend has now started using it and has not told me about it. Should I be upset? How would you react?