Open Question: Stay-at-home moms (or female nannies) of young boys — how do you teach them how to be boys?

My son is almost 2 years old, and I stay home with him full-time. His father works all week and travels frequently for business, so my son spends the bulk of his time with me. As a result, he wants to do things like paint his toenails, wear make-up, try on my high heels, etc — because he spends all day with me and sees me doing those things. I explain to him that he’s a boy and those things are for girls, and when my husband is home we try to have him spend as much time with our son as possible, but I’m curious how others handle it. I know that as he grows up, he’ll figure it all out, but in the meantime, any tips or tricks? Thanks!