Merry Christmas! I hope everyone is healthy, happy and writing during the holiday season.
As an exercise:
Think about what your character would give the person they love for Christmas. Would it be a giant teddy bear (Die Hard), a musical cue card presentation (Love Actually) or a VCR/towel (Scrooged).
By determining what your character can and will give the person they care about most, you will better understand the true nature of their nature and relationship.