Hi guys!

So I recently adopted a kitten and brought her home. She has her own special place to sleep, eat and poop (the bedroom, which is already off-limits to our other kitty). 

I introduced them after a couple days of sniffing each other through the door, and placed her in her kennel in the living room for a safe face-to-face meeting. Both did well. Big Brother pawed through the bars of the kennel and Baby Cat batted back playfully. Everything was going smoothly. 

I let Baby Cat out, and we played with her toys in the living room while Big Brother watched. He got curious and came over after a little while. He stood over Baby Cat and began to groom her. 

"Omg, how effing cute!" 

I was so excited that they loved each other. I was picturing them cuddled up in the same bed, playing together, matching outfits...

But that fantasy was crushed by a squeal coming from Baby Cat. Big Brother had her completely wrapped in his front paws and was biting her *hard*. 

Now I can't leave them unsupervised together. Sometimes he will come up while I have her on my lap and groom her a bit, and then go back and bite her again. And these are not playful nips, either. Its breaking my heart that he's being so mean to her after what I would have deemed a succesful introduction process. 

He's currently wearing a calming collar, I've tried spraying him with water when he gets into "pounce mode," I hold her butt up to him so he can check her out, I get them to play with the same toy, but as soon as he stops playing, he pounces on her. I feel awful admitting that I've given him a pretty decent whack on his butt, and he does leave her alone for a little while after that, but I don't want to make that a regular thing.

I am totally out of ideas, and I am not going to re-home or return anybody. Reddit, please help.
user
Older cat seemed to be okay with new baby cat, but is now pouncing and biting her when ever he
assistant
Hi guys!

So I recently adopted a kitten and brought her home. She has her own special place to sleep, eat and poop (the bedroom, which is already off-limits to our other kitty). 

I introduced them after a couple days of sniffing each other through the door, and placed her in her kennel in the living room for a safe face-to-face meeting. Both did well. Big Brother pawed through the bars of the kennel and Baby Cat batted back playfully. Everything was going smoothly. 

I let Baby Cat out, and we played with her toys in the living room while Big Brother watched. He got curious and came over after a little while. He stood over Baby Cat and began to groom her. 

"Omg, how effing cute!" 

I was so excited that they loved each other. I was picturing them cuddled up in the same bed, playing together, matching outfits...

But that fantasy was crushed by a squeal coming from Baby Cat. Big Brother had her completely wrapped in his front paws and was biting her *hard*. 

Now I can't leave them unsupervised together. Sometimes he will come up while I have her on my lap and groom her a bit, and then go back and bite her again. And these are not playful nips, either. Its breaking my heart that he's being so mean to her after what I would have deemed a succesful introduction process. 

He's currently wearing a calming collar, I've tried spraying him with water when he gets into "pounce mode," I hold her butt up to him so he can check her out, I get them to play with the same toy, but as soon as he stops playing, he pounces on her. I feel awful admitting that I've given him a pretty decent whack on his butt, and he does leave her alone for a little while after that, but I don't want to make that a regular thing.

I am totally out of ideas, and I am not going to re-home or return anybody. Reddit, please help.
user
New kitten is getting butt-bitten by her adult brother, even though they were introduced well before that. What can I
assistant