My Teacher's Pet Isn't So Great Anymore

Okay, so I kind of lost my cool the other day. My teacher's favorite has been bragging about getting an A on a test he totally cheated on. Yeah, I know it sounds bad talking like this, but come on! He copied from me during class and then made up some story about studying all night. I confronted him in front of everyone today, even though I knew the teacher would be upset with me for it. Am I just overreacting, or does anyone else feel this way?