From Wikipedia: "Child sexual abuse is a form of child abuse in which a child is abused for the sexual gratification of an adult or older adolescent."

Now I'm wondering where boundaries run between physical and sexual abuse. Is it sufficient for a classification as sexual to include traits of sadism, or does it have to involve indecent exposure?

What if the adult abuser is not rationally aware of a sadistic motivation, where she gets sexual gratification without admitting it to himself? Or is the experience of the abused, for instance the extent of humiliation, the more important criterion?

Sorry, this will be triggering. I try not to be too specific, but I'd like to get some opinions from the community.

If the fully dressed child is restrained by wrists and neck into a humiliating position to be beaten on the buttocks by the likewise fully dressed abuser, is this clearly physical abuse or in a grey area?

What if traits of sadism mix in with nudity? For instance, a dressed adult beating a naked child with an object, like a shoe or cane, without touching or aiming for genitals, but with a ferocity that the child feels terrorised, and is later ashamed of body reactions?

The abuse involving nudity affected my self-esteem more severely, similar to what victims of sexual abuse report. But then forms of abuse where genitals are touched may still be way worse, and I haven't experienced these.

So is this clearly physical abuse, is it in a grey area, or how does one correctly differentiate between physical and sexual abuse?