How do I deal with a friend problem?

So I have 4 friends, ( 1 I dont want to be friends with, the one I have a problem with.and they know me as the funny person, the one that has all the humor. So, I tell jokes and that kind of stuff. I don't mean it of course, but I tell jokes about them and they laugh at how funny it is. Except for 1. This "friend" has been friends with me for a while, but he seems to annoy me ALOT, so I don't want to be friends with him. But I just want to make my friends happy and just pretend. Here is the problem. He takes the jokes I say seriously. And what I say isn't even true about him. He will be like, why would you say that I am like that!? That is so mean. This is Ben going on for a month. He started to get me annoyed, so I slowly started telling jokes about him more then others. Now that 2 months have passed, I am ashamed of myself.I now only tell. Jokes about him. I want to stop but my friends are now like, you are the funniest person I can be friends with! I don't know why but I keep going. Now on the friend that is getting the jokes told on, I feel so horrible now. He is all depressed and is saying I am a bully. I feel horrible because I think I really am one. But here is the worst part. He is threatening me to report me to a teacher about me being a bully. Here is the worst part, my parents always call me the best ( don't worry, I'm the only) son they could ever have and I'm never inappropriate. They are overprotective about me, and if they found out I am a bully they wouldn't talk to me for months. I am a bully. I can't stop. I don't want to get reported. I don't want to lose my friends. Now I am getting depressed about it myself. I feel horrible. I don't know what to do. Tryied to ignore him, it didn't work. I tried to be nice, and he accused me that I was faking to make my friends laugh. What should I do! And fast, he could report to me at any time!