Screeching, spitting for fun

My toddler is 26 months. He is a very happy, sweet, smart…and mischievous kid.

Lately he has started screeching at the top of his lungs and smiling. I’ve tried ignoring it, saying we don’t scream in the house we can talk/whisper/sing (tried to make it fun by whispering whisper and singing sing, which, on second thought, probably encourages him), saying we only scream outside, if you feel like screaming tell mama and we will go outside.

He’s also started spitting on the floor. Saying we spit in the sink if you feel like spitting tell mama and we will go to the sink also doesn’t work. Ignoring it doesn’t work. I’m at a loss.

Its really triggering to me to have him blatantly disregard me. I try to keep my cool but I can feel myself getting angry. I also have a newborn and him screeching right next to her ears isn’t safe.

SOS?