Guys, What does a guy mean when he calls you a good girl?

Anonymous
I was in class the other day studying for my ap history exam when a guy who I've known for about a year came and sat next to me. We talked for a bit and then for some I reason I can't remember I began to talk about my friend who happens to be a pothead. When I brought her up he started laughing and said,"I still don't understand how you two are friends". When I asked him why it was so confusing, he said, "Becasue you're a good girl and she's like the biggest pothead I know." When I tried telling him that I was not, he pointed to my textbook (which is covered with sticky notes) and said,"That's being a good girl".
I'm in the top ten percent of my freshman class so I'm kind of used to comments like that but it's just that coming from him... His mom is an English teacher at our school, he's an honors student as well and his history textbook is probably more used up and damaged than mine from now much he has used it.
We were at one point talking/ sort of on the verge of dating and he still flirts with me however at the same time I hear rumors from his friends that he's talking to a girl from his church and I was just wondering what you guys think he meant when he said that Im a good girl. Is it a bad thing? Is it a compliment? Or is it that I'm overanalyzing this situation and he meant nothing?
Guys, What does a guy mean when he calls you a good girl?
4 Opinion