Okay. First of all, Rusty is the fluffiest kitten in the entire world. Which means you really have to get in there and part the masses of fluff to see anything in the butt and genital area. Secondly, when I first checked him, he was still being incredibly skittish and had NO DESIRE to have his butt and genital area checked. Thirdly, one of his testicles (and how big is a six-week-old kitten's balls, anyway?) hasn't even descended.
So. I looked briefly. Thought I saw what looked like female equipment to me and never checked again.
But yeah. I should have.