3 year old keeps asking me (mom) to smell her butt. Is that... Is that normal?

I'm hoping its just a phase as she asks me to smell her feet and arms, etc. I try telling her its rude and not nice to ask people to smell her butt. She just laughs. Note that she likes to be naked at home at night and I have no problem with that. I want her to be comfortable with her body as I was always made to be ashamed of mine.About a month ago she asked me to smell her finger and I was smart enough to ask where it had been and she proudly announced that it was in her butt. Ew.What do I do? I don't want to punish her, but convince her and teach her that this is not nice. I'm assuming this is something kids just go through while learning about their body. Is that wrong? Is this something weird or is it normal? via /r/Parenting http://ift.tt/2wauUtT