Jew Jokes: Funny or Offensive?

So today was one of the greatest days I've had here. It was so nice, sunny, and hot. The school had a bbq so we had free food and BROWNIES and mostly just chilled outside all day. But I did not have the perfect ending to this day. I had dinner with my group of girls that I've been hanging out with and we watched Glee that was great, but then after they started talking about this kid they played soccer with today who they all think is really nice. Then one girl said something about how all the Greek kids come to him for pot and then everyone else sort of agreed they lost respect for him. But when I told my story about how when one of the other Jewish girls told him she was Jewish his exact words to her were "so who are you going to swindle out of money today?", nobody had any problem with this. So... pot=not ok and making offensive remarks about someones religion=ok???? Not only that but they all stood up for him! They talked about how people joke about that and bla bla bla. One girl even said something about how I can't classify people like that and not like him just because of that.

I don't know, so I'm posing the question to you guys (even though I know it's mostly my family of Jews that will read this). I think Jew jokes can be funny sometimes when the Jew is joining in or in movies like Harold and Kumar or Borat, but where is the line between joking and offensive? Just because maybe he didn't mean it badly does that mean it's okay? Do I have a right to be offended or I am I overreacting? I feel like just because it's seen as normal behavior doesn't mean that it's not offensive and shouldn't be pointed out as such and changed. I also feel like any of my real friends would have stood up for me in this situation. Correct me if I'm wrong though, maybe no one would have stood up for me because there's nothing wrong with this and I'm being silly. That's why I need some opinions on this issue!