Is it okay to ask a belly dancer for a lap dance?

I'm at a going away party at a bar and they have a belly dancer. It's the first I've seen a belly dancer at a bar. The belly dancer came over to me and I, stupidly, asked if she does lap dances. She looked angry and simply said no. She walked off and I don't want to be rude just ignorant. I thought it was an okay question. I would never ask a random woman for a lap dance. But the fact that she was belly dancing leads me to believe she's performing a titty job.