From a folk point of view, you and your boyfriend should get married before your grandmother died, or after your grandmother died, after three years of mourning (ordinary children) and one year of mourning (ordinary grandchildren or collateral relatives). If you are engaged, the wedding date should be postponed, or both parties should go to other places to avoid attending the funeral.

If you attend the funeral from an emotional point of view, please decide in what capacity you will attend. China is a vast country with different customs in different regions. In some areas, it is hoped that relatives and friends will be widely invited when weddings and funerals are held, so red events will increase joy and white events will increase mourning. Therefore, in some provinces, some people still hire mourners to mourn.

If you only attend the funeral as a friend, you should not go to Dai Xiao, because you are not a victim. Although your boyfriend is suffering, as a guest, don't stay in front of the spirit for too long and don't kneel for too long when crying. You should always stand on the side of the spirit, or outside the temple, until the end. You shouldn't bow down except to help the soil when you are buried. You should choose low-key clothes, do not wear gold and silver objects, and do not wear big red or big green ornaments as gifts.

If you attend the funeral as a relative, but you are not familiar with the deceased, you should wear non-gold and silver jewelry with logo when you are in Dai Xiao (I don't know why the following text can't be entered, so I added it in the comments).