It works just fine. There are male calico cats out there. Very rare but they indeed exist.

About one in every 3,000 calico cats is male. The genes that control whether or not a cat is calico are on the X chromosome and there must be two X chromosomes for the genes to be expressed, therefore the calico males usually have Klinefelter's Syndrome which causes a XXY chromosome structure.

Male calicos are usually sterile.

The extra sex chromosome that enables male cats to have the calico or tortoiseshell pattern also renders them sterile, so it still doesn't work.

Maybe it's a step-dad kitty?

There have been cases of klinefelter's syndrome where they were not sterile, but it is very rare. So this scenario, although not plausible, is possible.

Does it really matter? It's a picture based on an FML, not scientific research.

This has got to be one of the most hilarious debate/discussions I've seen on an FML recently... You all win. (And clearly the mommy cat was having an affair, so she and the daddy cat got divorced and now the daddy cat bought his own set of boxes and didn't give his middle child one because she knows the truth.)

That is the first thing I thought when I saw this...

I'm pretty sure all male calicos are either going to be sterile or hermaphroditic. But it doesn't matter, because it's still just a picture lol

The big bro is also a calico. That would make the family even more rare, or possibly point to another cause than just the presence of XXY chromosomes. Also, another alternative to kitty-klinefelter's is the possibility that the male calicos (sp?) are chimeras or experience mosaicism. That being said, it is a rather creative and visually appealing cartoon. One of the better illustrateds, IMO.

Does that mean you plan to live with your parents forever? o_o;