How to tell if kitten is lonely?

Hey there! I have a 17 week old ragdoll, he’s male so he’s basically a scarf - the breeder described male cats this way and she’s right so far, he’s always cuddling me or using me as a sofa.

He has load of energy and we play with him a few times a day or basically whenever he demands, since we work from home.

Since the breed traits are to follow us around and be vocal, I’m actually not sure what signs to look out for to see if he’s lonely. And I’ve just wanted to keep an eye out and make sure we get him some company if he needs it.

Ideally we wouldn’t have a second cat, but ofc I love my fluffy boy and want to make sure he’s happy. 🥺