stuck on

adjective3

1. •
   Puzzled or stumped by.

   • "I'm doing today's crossword puzzle, and I'm stuck on this one clue." — 2007
2. •
   Fascinated by; enchanted by.

   • "I'm stuck on the way you sing that [Edvard] Grieg song," he declared. — 1915
3. •
   (slang) Infatuated with; romantically attracted to; in love with.

   • McTeague had a vague idea that Marcus Schouler was stuck on his cousin Trina. They "kept company" a good deal. — 1899