Hard to tell from that pic. Look for a genital opening. On male kittens, the opening is far or clearly seperate from the anus. On female kittens, these two holes are close and would seem to be part of the same unit or same biological assemblage of parts, if you will.
A black cat, an unclear picture. . .hard to say. But the way the light reflects sort of looks like a full-grown tomcat's testicles. Is this a kitten or a grown cat?
Anyway, yep, if those are "big ones", it's definitely a male! :lol3:
It's really hard to say, because I'm not really sure what I'm looking at. I guess I'd say a boy, due to the "big ones" that seems to be pictured. But, if you see another opening in the section that we consider big ones due to the lighting, it's a girl.