If someone was basically forcing me to play piano and I didn’t want to play, I would be completely honest and say no thanks. There’s no reason to lie. I know some people who just say yes to anything. For example, someone might buy you a present that you didn’t want but you still say that you liked it anyway because you didn’t want to hurt the persons feeling. In this case it’s messed up because in reality you didn’t. Therefore, I wouldn’t want to waste anyone’s time when there is actually a kid out there who really wants to learn how to play the piano.