Hi! This is my first time posting on this site. I'm so hoping to get help. I have 2 cats - Koa (6 yrs old, fixed male, Siamese mix) and Hunter (3 yrs old, fixed female, domestic shorthair). Both cats are super friendly and Koa is Mr. Personality-everyone loves him (super social). Koa has always been the alpha cat and Hunter has always been a shyer cat (they have been together 2 1/2 yrs). About 2 months ago, Hunter started hissing at Koa anytime he runs to play with her. It's like she's had enough of him. He seems more aggressive now that she won't play with him. It's really frustrating b/c they used to get along for the most part, sleep together and groom and really have no tension. Now it feels like there is tension constantly and she hisses at him at least twice a day (that I know of since I'm not home all the time). When they eat together it's fine, when I play with them together, is fine. It's just when he's not distracted or sleeping that he seems so interested in Hunter and she's not having it. I have tried Feliway diffusers, Bach rescue remedy (for Koa-just started that 4 days ago-seems to help a bit), Zylkene (for Hunter-vet gave it-it's just an herbal supplement-made Hunter more confident/less shy), playtime every night, but this is still going on. They have plenty of cat trees, resting places, toys, litter boxes, etc...Is Hunter just setting new boundaries for Koa? Will he eventually get it? I worry that someone will get hurt (luckily no injuries thus far). It's keeping me up at night b/c I'm worried something will happen. Any help would be great!! I'm seriously losing sleep b/c I love these cats like they are my kids and I just want them to be happy! Thank you all.