Robin snuggles with me more than he used to. He PURRS a lot more than he used to. But... He's determined sometimes to get his way. When I stop him from playing with things he's not supposed to,he'll fight me tooth and nail! If he has a case of the crazies,and I pick him up so he won't wreck the place, he'll wriggle right out of my hands! When I leave,he'll cry at my door! He's becoming much more aggressive with the downstairs cats,this morning he acted like he owned THEIR place. He's rambunctious-he loves when I say that -rambunctious! I love him-as he is. But he has to learn his nicey-niceys!
You didn't say how old Robin is, but if he's between 4 mos and under a year old, he has the teenage crazies and brattiness. Sounds like pretty normal male behavior to me. Is he neutered? If not that could explain an increase in aggressiveness. Remember to reward and praise him for good behavior and when he is being nicey-nice.