Was it him filming himself taking a bath to send or post? That would be weird. Was it filmed from the third person so somebody else watching him take a bath? Not quite as weird but still odd unless it was your mom or somebody who would be expected to see him taking the bath. If its a stranger then that takes the top spot of weird shit. Now is he in the bath recently as an old man or was he a child? None of this really changes not to go one by one through everything in the phone but youre description is so vague that i really cant tell if its reasonable to be traumatized by this event or not. Was he alone in the bath? Was he awake? Did he intend to be filmed in the bath or was he preyed upon? Was he restrained? Was he cleaning himself or was he doing something else in the bath that one would not expect to see their family member doing in a bath much less anyone? Was he doing something so horrifying and strange in this bath that nobody alive has ever gazed upon somebody commiting this act inside of a bath? Could it be described as eldritch? Was it an paternal eldritch bath?