XXXXXXX (whoa you have a lot of X's),
I'm sorry to hear about your situation, and your canceled wedding. If you two were in love, you owe it to him to tell him about the no contact. I think it would be mean to just stop answering, just be honest with him and tell him goodbye for now, either by phone or email or whatever. You will upset him if you just cut him off without telling him why. Good luck to you
