What can you do when your boyfriend accused you of cheating but you didn't and he won't let you explain?

If he has so little trust in you and won't even ask you what the truth of the matter is, it may be you're better off not to be in a relationship with him. There's very little you can do but email or leave him a message saying you still would like to talk to him about what went on between you two but will respect his wishes and not contact him again. Leave the ball in his court. Your boyfriend has probably come from a family where one or both parents have cheated, or some ex girlfriend has cheated on him and he is now not confident in his future relationships. Give it one more try with him and if he doesn't give you a chance to express yourself then move on no matter how heart-breaking it is. Don't cry over spilled milk and be firm with him and say, "When you start accusing people of things they didn't do then you should be mature enough to sit down and talk it out. If you don't then you have the problem!" Don't cry and carry on over this with him because it makes you look guilty. Stand firm, and NEVER let anyone treat you in this manner. Remember, you know who you are and that you haven't cheated on him. That's all that matters.