Kurt laughed a little. "I don't know about groovy," he shrugged, eyes lowered, but then he looked up at Raven - appearing somewhat shy. "I, uh..." It was most likely apparent that he usually didn't talk about this freely, but if she was asking about mutants and was the Professor's sister then she must be one herself.
It only begged the question: Why hadn't Charles mentioned a sister? Wouldn't he, if they were still close? What had happened? ...that was a lot of questions, but Kurt figured he had time to get them answered.
"I teleport," he said. "And I don't...er...I don't exactly look like this, let's just say. What about you?"