I usually reply with a sweet smile and, "yes, a LOT." This tends to catch people off guard. As though they weren't expecting the answer to be honest and, literally, painful.
Although, I've gotten used to the pain (sorta), it still hurts to be tattooed. Kind of like the worst papercut you've ever had, but over and over again for several hours. Apparently, someone wasn't quite as honest with this woman about what it feels like.