Is it okay for my kitten to eat cat food?

I have a kitten who is about 2 months old. I also have two other cats who are about 3. They are obviously on cat food, but I have different food for my kitten. He although thinks he should eat their food. He will sometimes eat his kitten food, but seems to prefer their food. Is it okay or should I try and get him to just eat his kitten food?