I told him/her everything
Se lo conté todo.
I told him everything.
Volé a Roma y se lo conté todo a él.
I flew to Rome and told him everything.
— Cónclave (2024)
Se lo conté todo, no pude aguantarme.
I told him everything, I couldn't hold it in.
— Moscú no cree en las lágrimas (1980)
No se lo conté todo.
I didn't tell him/her everything.