unbullshitable

adjective2

1. •
   (slang) Able to see through bullshit; not able to be fooled.

   • He was every inch the cop now, unbullshitable eyes trained on Kate's face. — 2001
2. •
   (slang) Not supporting any but a straightforward explanation.

   • He has done backed his ass into an unbullshitable situation and now he's desperate. — 2015