A simple romantic and warm song is very suitable for wedding background music, and I believe it will be loved by most brides.
The Family by Fish Leong and Zhang Zhicheng
The lyrics of the song "Will you love her forever, will you take care of her, whether rich or poor?" They are all adapted from wedding vows, and of course they are also very suitable for romantic weddings.
You can also find songs that often appear in happy birthday weddings and choose a guitar music suitable for your girlfriend.