my 17 year old male cat keeps howling and following my 2 year old kitten around. Hes a male, been desexed AGES ago, he’s never been in heat before, so I don’t think he’s in heat. my kitten is constantly being followed around and she doesn’t like him yowling and following her (she’s also desexed)

I don’t know what his problem is, and it’s only her out of my 3 other cats. He has 2 other brothers and my other girl is 4 years old.

Hes never done this before, I will take him to the vet, but can anyone tell me what it possibly could be???