I thought of a way to deter Kiki, especially after the MayDay incident.
I placed a sarong in front of the gate, secured by two big paper clips. Kiki couldn't see what is going on in the house, he being only 2 feet tall.

I was trying it out, and Spencer was outside with Kiki.

Once Spencer saw the barrier being put up, she panicked. And she pawed at the cloth several times, whimpering. Kiki just sat there calmly.

Spencer, highly agitated.

Of course I let Spencer in eventually. She peeped at Kiki from the inside.

Kiki didn't try to squeeze through the grilles, or paw at the cloth. He just sat on the steps until 11pm, waiting for the curtain to lift.

It has been three days now, and it is still working. Kiki waits for me on the corridor when I come back. I would let him in, feed him, wait until he leaves, then I put the cloth up. He would wait outside until late, then he goes home.

I think this works better than the plastic netting, because he can't see us.

Tonight Spencer wanted to take winds outside. But when she saw the gate being locked, she panicked again. Eventually I left the gate ajar, but the cloth was still in place. I peeped at Spencer, she walked in and out a few times without problem, and she was satisfied.