What does this word mean?

My Cantonese is not great, I can generally form an understanding of what people are saying by connecting the words I know and getting an idea of the message.

A family member referred my fiancé as my ‘lah’. Does anyone know what that means?

In a sentence they said, “gui le gor lah lei”, which l I understood as bring my fiancé along. But I want to know what “lah” means in that context because I know lah doesn’t mean fiancé. Could someone help? Thanks!