Hey, I adopted a kitten 5 weeks ago and vet told me that he was 6 weeks old at that moment (apparently not). He was lonely, so I decided to adopt another kitten 3 days ago. My older cat always go for the neck of the other one and today he managed to bite him from his neck and he started to hump him. At first, I thought that the older cat is trying to show he is the boss but when the younger one screamed I pulled the older cat and his penis was erect. This was a surprise to me since I thought he was 11 weeks old. Younger cat always feels threatened when they are awake because of the older cat always tries to rape him (there is no problem when they are sleepy). What should I do?