Why come wayne never treated kevin like a friend or brother on the show even tho they were only 2 to 3 years apart in age range ???

https://www.youtube.com/watch?v=n3eJkf4erbI
https://www.youtube.com/watch?v=n3eJkf4erbI
https://www.youtube.com/watch?v=n3eJkf4erbIhttps://www.youtube.com/watch?v=n3eJkf4erbI

2 to 3 years is alot when teenagers