Do you ever deliberately piss people off to make them more angry?

There is this guy at work who's a huge lady gaga fan and if you say anything bad about her he goes into a psychotic angry fit. I don't think she's a bad signer, she's ok but i'm purposely telling him she's terrible and talent-less and i'm telling him paris hilton sings better than her. Well i'm just saying whatever to get him more angry. This guy is such a fan that he's crazy about it, i wouldn't be surprised if one day she gets a restraining order against him for stalking her. Anyways, he's used every word in the dirty book against me and is threatening to kill me, i'm getting him more mad by the minute at work. I want to see how devoted he is to her, how far he'll go. Did you ever piss someone off deliberately knowing they'd get angry and kept doing it for fun?