Nude photos involving family members: acceptable vs. unacceptable ones.

The nude photos with my father that I agree to take are for his modeling work.
These are photos showing the family in harmony, enjoying a wonderful summer vacation.
The photos I refuse to take with my father are of his models.
where you see a father placing his hand on his daughter's shoulders or around her waist, or casting an inappropriate look at her.
It completely changes the meaning of the souvenir photos; they become something else entirely.