carry a torch for
US /ˈkæri ə tɔːrtʃ fɔːr/
UK /ˈkæri ə tɔːrtʃ fɔːr/

1.
sentir algo por, estar enamorado de (sin ser correspondido)
to have strong feelings of love for someone, especially someone who does not feel the same way about you
:
•
He still carries a torch for his ex-girlfriend, even though she's married now.
Él todavía siente algo por su ex-novia, aunque ella ya está casada.
•
She's been carrying a torch for him since high school, but he never noticed.
Ella ha estado enamorada de él desde la secundaria, pero él nunca se dio cuenta.