Clue: I hear an American poet solved the riddle of the pseudo hotel patron … (7,5)
Answer: MYSTERY GUEST
Explanation: Definition: pseudo hotel patron
=similar to a 'mystery shopper', someone who stays at a hotel in order to review the experience.
 Homophone/"I hear" of: 'Mister E. Guest'=Edgar Guest="American poet" ;
 Also a Homophone of: 'mystery guessed'="solved the riddle"