I hope it's okay to ask.

I was wondering how I can have Kamala notice Marcus' behavious in Act 2? I've tried multiple times but I guess i'm doing something wrong. Any help would be appreciated.

Of course it's okay to ask :) I answered this on the Steam's discussion. I'm not sure if Itch.io supports spoiler tags yet, so I'm linking to the the Steam discussion (and answer) here.