strange behaviour

Question
ok well i have 2 male domestic cats one aged 3 years and the other 1 and a half they both get on very well and have been together for over a year now they get on so well that they lick each other and sleep with each other to but over the last month the younger one has starting to plulp the other one's fur and causing scabs but the other one doesn't seem to care and it seems as if its not hurting him if i seem him i tell him to stop but i don't want to stop their bonding and i cant see what he is doing all the time

also the older cats licks me all the time and not just now and then when even he gets the chance and he loves doing to the point where you can here him purr at the other side of the room i don't mind it because it keeps him happy and its like we are both bonding to but wanted to know why he is doing it as he has always done it from when i got him at 9 weeks old

please help i'm at a loss now :(

Answer
Hi Will,
Thanks for writing! Happy to hear they are getting along so well! and doing what bonded kitties do which is groom each other just like when their mom groomed them as kittens. (They carry on this behavior when bonded to another cat).
I am not sure exactly what the younger one is doing. you mentioned he "plups the other's fur"??
Grooming each other is 100% normal and is mutual grooming is a sign of affection and that they are at ease. That is nothing to be concerned with.
I have a question for you about the scabs-are you sure it is not the 3 year old doing it to himself from biting or scratching an itch himself with his mouth by using his own teeth when he is grooming himself?
I don't have enough information to know, but generally a cats tongue is pretty sandpaper like and to incessantly lick the same spot would lead to what is called a "hot spot" it would be red and inflamed and raw. Kitties inflict this on themselves when they are incredibly itch and uncomfortable..to relieve the itch they bite at their flesh..
If he has little tiny scabs or bumps  all over his body or his rump is  what is known as miliary dermatitis all over him-then that is an allergic reaction and from his own internal processes, an allergy to fleas or a allergy to something else.
It doensn't sound like the little one is biting the older one so i am not quite sure what you are describing.

Is the young one obsessively licking the same spot on the 3yr old?  Is he is orally obsessed & sucking?  i generally have seen that behavior due to improper weaning when humans mistakenly take kittens from their mothers way to early they actually traumatize the natural process and/or  this could happen if a kitty's mom dies or is for some reason separated from the kitten at too early an age..
I am not clear on what exactly is happening with your cat's so am just giving you some potential scenarios.
Sounds like your older kitty is grooming you, this is fine...The only time i have seen it become an issue or when i recommend re-directing a cat's attention is when it leads to the kitty biting..Sometimes cats will groom and then get overexcited or "overstimulated" and bite pretty hard..if it is a "love bite" and just touching your skin with his teeth-no big deal, - if he is breaking any skin-then we would want to modify the behavior before it gets obsessive.. It doesn't sound like this is your problem here...IT IS FINE FOR HIM TO GROOM YOU IF YOU DON'T MIND...His mom probably took care of him the same way when he was a youngster...
hopefully i have answered your question!