My friends father is or was having an affair for years why can't she say something?

My friend her father has been cheating on her mother a few years. She never talks about it but I know she is very mad. She was in therapy for awhile but didn't say why.

She didn't go to prom and refused yearbook pics saying it's because she's mad her father moved her to another state 4 years ago.

I asked how come Noone says anything to her father including her. She says it's complicated. She said she thinks he's not with the other lady anymore. Thinks

Why would she not go crazy and say something to her father? Oh she's 18 in college. Her mother is a housewife and older I think like 50.

My friends father is or was having an affair for years why can't she say something?
Post Opinion