I feel the same way, Aldebar. My dad is really passionate about football too, and he yells really loudly and claps when he watches it. He seems to get violent sometimes, especially if his team loses. Just the other day his team wasn't playing so well and lost, so My dad was pretty much yelling the whole time it seemed. I was really afraid to say anything to him after the game because he was acting really angry. I used to really like watching sports, but I've realized what it does to people.
P.S. I hope your your friend is alright.