> pronounced "infeasible" as "in-THESE-able."

What other way could you pronounce it?

https://www.google.com/search?client=firefox-b-1-d&sca_esv=0...

...unless you're saying he pronounced the 'F' as a 'TH'?

> pronounced the 'F' as a 'TH'?

That’s how I read it