I need you to decide, was I bullying this kid?

Okay, so I'm a girl, and I recently gOt in trouble with my friend because we were apparently "bullying" this guy. Now, the guy was an ex boyfriend of a girl I was previously friends with, and in like march she broke up with him, and he always was mean and said she was ugly and had no chance with her new boyfriend. He also was just mean in general and got his friends to be mean to her. Alot of this occurred in march. The thing with her new boyfriend happened in early may. Now, back when this was just starting in march, I began to hate him. I had some problems with him that were eventually settled out. In the middle of April, he became mean again to my friend and he always stared at me, and when he did I made a face back. Then, one day he wore all plaid so I called him a platypus and he laughed so I thought it was alright. One day in English, he and his friend sat in front of my friend and I and they were bein loud, so I asked my teacher if they could move so we could work and he said alright. I told them to move and stuck my tongue out jokingly. The guy who i was having issues with kinda stomped away and the teacher confronted him. The guy told him about the platypus thing and the staring thing and the thing where I stuck my tongue out. My teacher got all pissy and called me in the hall and like told me I was being a bully, and he wouldn't even allow me to tell my side of the story. Then, he told me I have a lunch detention for the rest of school (2 weeks) and I don't think it's very fair. Give me your opinion, was I being a bully?