Is anyone else unsure if people are being racist or just tying to be funny?

My fiance's family are all white. I'm a quarter white so it's not this huge difference they're making it out to be. Im native american, Oneida enrolled, grew up on the reservation with my huge family. I've never been into dancing and the Pow wows like both sides of my family. I'm not walking around in traditional Oneida dresses or eating Fry bread every day but they say the rudest things that just rub me the wrong way. I'm not sure if I should say something or if they're just tying to be funny, yet accepting? His mom cracked a joke asking me if I caught wild buffalo for thanksgiving, they'll slap their hands on their mouths and make "indian" yells. His grandma was giving away family belongings, trays, wedding gifts, kitchenware, pictures, and she gave me native american salt n pepper shakers. It was pouring rain and at least 3 relatives of his approached me and asked if my family was doing a "rain dance" that day. I think my awkward laughing right away instead of saying something made it seem okay. I don't what to do. It was not a big deal at first, four years ago. But now every time I hear it I get really pissed and offended. I don't understand that kind of behavior I guess.