A lot has been said about gender identity. To that I'll add that a two-year-old boy who is happy in a dress might be equally happy in more traditionally masculine clothes. When my son was two, he was pretty much oblivious to what he was wearing. The key is that Charlie is happy. As long he's happy with his clothes, what does matter whether those clothes come from the boy side of the store or the girl side? His grandparents need to chill.