How would you react if your stepdaughter reached out and grabbed your penis?

I don't have a daughter but if I did, I'd sit on my hands and let her touch it, look at it good, play with it to discover and explore everything about penis. Answer any questions she may have and etc. Proper sex education, ya know. It's probably better that way than her fooling around with boys who would just take advantage of her to get sex and/or even get her pregnant and run away. That's my opinion.