he, she, etc. isn't having any
be not having any (of it)
1. To not want any part (in something); to be completely disinterested (in something). My mother wasn't having any of it when I suggested she come bungee jumping with us. Hiking in this weather? No thank you, I'm not having any!
2. To completely disagree (with something); to not believe something at all. I tried to pass it off like it was the dog that broke the lamp, but my wife wasn't having any of it. We laid out our reasons for voting "Yes" in the referendum, but our neighbor wasn't having any.