male cat humping.

Nicky tried to mount the new kitty (whose name is L'il Meow Meow. I changed it.)

Ah! Do I let him try? Or stop him? Or what!?

If their not both spayed and neutered the answer is yes,

Jake (12) tries the same thing with Jaz (11). He usually does it after a chase around the garden or house and will then try to mount our Jaz.

She doesn't take too kindly to his amorous advances and he gets a face full of hissing, spitty ginger cat for his trouble.

They are both neutered and i believe it may be a dominance male thing.

they're both fixed!
L'il Meow Meow is like.... 5 months old compared to Nicky's 9 months... and L'il Meow Meow is frisky and playful. It's hard to tell if he's playing with Nicky - or trying to assert dominance.

They chase each other around and one of them hisses, I think it's the little one, but this morning, Nicky was all like "I'm going to mount you!"

Weird.

Yeah I'm not 100% sure.... L'il Meow Meow is totally playful... Nicky usually is too, but I think because he hasn't had a LOT of exposure to another cat...

They tear-ass around the house all the time but the little one is the agressive one, from what I can see...

So Nicky just decided he was going to him who was top cat, I suppose!