I personally am a huge fan of the term "Froot Loop" to describe my child (lovingly) under similar circumstances, but "dork" works pretty well here too. Let's just say that I've seen similar things from her. Oy. The baby-oiling-of-the-cat-and-then-attempting-to-hide-the-evidence-with-a-kitty-bath incident. {cringe}

Because, see, it really does happen that there are times when SOME kind of term like this is necessary, but drawing parallels to another disadvantaged group probably isn't it, as Colinsmum notes.
I run in social circles where the term is reasonably offensive, and I live in N. America. The "R" word and all of its slang permutations is similarly offensive to many Americans. I can't speak for Brits on that one.