I have a 2 year old male cat. I recently took in a kitten that a friend's son had found, and my male cat, Gomez, is letting the kitten nurse off of him. Is this something I should be worried about?
I had that happen to me one time with an 18 month old male and a 6 week old kitten. My adult actually enjoyed nursing, and the kitten was very happy about it. They formed a very strong bond as adults. I see no harm in it.
And just a warning - don't be surprised if your male starts to lactate. Given enough stimulation, they will give fluids (and leak when the kitten is not nursing). I asked a vet if there was anything nutritious about it and they honestly didn't know. I googled it a while back and didn't find the answer.
Think of it as a way for them to bond with each other.