I just adopted a 9 week old female kitten about two weeks ago. I have an older male kitten who is 9 months old and have had him since he was 12 weeks. He’s been neutered since we got him, and has always been a very normal and nice cat, cuddling in the bed at night and overall being really sweet. However, we haven’t gotten to the point where the two can really comfortably be in the same room for long. Every time she’s In the room with him he just acts really intense, immediately chasing and knocking her over, biting her throat and legs and pinning her down. While he’s doing it she doesn’t seem to like it at all. She hisses, growls, cries, and tries to kick him off of her before we step in and separate them. However, she doesn’t always seem scared of him and seems to seek out play sometimes. He just isn’t calm when she’s around and seems hyper-focused on her all the time. We keep them separate 90% of the time because it’s just distressing to watch it happen and since he’s so much bigger than her we feel we have to stop it. I’m unsure of how I’m supposed to handle this because of course I want them to cohabitate well and get along, but I also don’t want him to hurt her.