My FIL keeps chasing/bullying the cat. He amps up the behavior when I'm home to get a reaction out of me. How do I get him to stop?

I joined because I was taking care of my mom, but my aging in-laws came into focus in the last couple of years as well. My MIL (93), an incredibly kind person, passed away in March. My FIL (87) is still around. Before she died, he was (with my husband's help) taking care of her. She was the household manager. She kept things tidy, paid the bills, did the taxes. Six months before she died, he began exhibiting signs of needing help too. He had a car accident, a couple of blown tires, and the home was starting to look uncharacteristically dirty and cluttered. At that point she spent most of her day sleeping in her recliner.

One day he just wouldn't get out of bed. He just refused and said he was fine and didn't want to go to the doctor despite not feeling well. When he refused to get out of the bed the next day (he was also saying some pretty crazy things), the hubs called an ambulance and he spent the next few days in the hospital with a UTI and prostate issue. He couldn't pass the swallowing test and refused any additional intervention and was sent home on hospice which ended three months later once he was fine.

When MIL died, the hubs and I did not feel he could live alone without help. He was forgetting to refill medications, missing doses, not handling the finances, not taking care of the home, and he was falling for people who call on the phone. He also had a fall out in the neighborhood while walking. We decided that the best course for him would be to move in with him and hubs stays with his dad all day.

Moving with us were our two cats. He's had a cat before. He talks fondly of that cat. He pets the neighbor's cat that comes to his back door. For some reason, he keeps chasing our cats. He corners them and makes sudden movements at them, shuffles his feet at them, shakes the chair when they are under the table to scare them, and claps at them. He keeps saying he's going to put them outside. He will then try to pet them, and says he wants them to like him. He meows at them (literally, he says "meow"). The cats are terrified of him. We asked him to stop, he said he thought it was funny. The hubs tells him not to do it, "I will if I want to". And then he plays dumb like he doesn't understand. "Really? You're not supposed to do that? Gee, I'm just a dumb old man. I don't know". I don't get it. And I'm at a loss. I know he likes his bits of what he thinks is funny. The husband says that when I'm not there he's better, but he amps up the behavior when I'm home to get a reaction out of me. I can't ignore him bullying a defenseless animal.

We moved in to help him so he wouldn't have to pay for caregiving help and preserve his resources. It was for his benefit not ours. We were happy in our own home. Now I dread going home from work every day. Any insight would be helpful. How do I get this guy to stop bullying these two very sweet cats? If he'd stop terrifying them, with time they'd probably come sit in his lap.