NPC's as family members

I created a character (PC) who is travelling with his father (NPC). I noticed that the game is tracking their relationship level, but this meter seems a bit off. I would like the AI to remember that these two are relatives, not friends, acquaintances, or partners. Not matter what they say to each other, they are not strangers and will stay loyal to each other. I cannot really just manually move the meter to ‘friendly’ either, because my character is currently angry at them for getting them in unnecessary trouble.

So, could you please add a tab for marking an NPC with a permanent relationship to a PC? People don’t stop being blood-related or childhood friends no matter what happens. Relationship can still be bad, but people don’t start making moves on their kids or plan to murder them, unless there is another tag for that purpose specifically.