Is It The Way I Said It?

I was visiting Offspring #2 room at college. I glanced at her bookshelf and among the college texts I could see only the top word on the back of the book. The word was "Parties." So I ask in what I thought was a normal tone of voice, "Do you have a book on parties?" I didn't think I was implying anything about this liberal arts college or the worthiness of tuition fees. But I'm guessing there was something in my tone because the answer I got was "It's Parties and Elections in America, Mom!"