Busy priest leaves sign for parishioners explaining that he doesn't need every detail of their sins.
Part of a priest's job is hearing parishioners' confessions—but that doesn't mean he needs to double as your weekly journal. One man of the cloth apparently decided that the needs of the many attending Saturday night mass outweighed the need of the few sinners who want to explain exactly why they cursed out their sister for forgetting the casserole at family dinner night. It's four Hail Mary's either way, Denise, it doesn't matter if you thought she intentionally forgot it because you wouldn't babysit her kids last week.
The backstory behind this sign is pretty clear: there was only one priest working this church on a Saturday, and he probably had to do double duty between confessions and Saturday night mass. In fact, Saturday night mass being delayed due to confessions going on and on and on is not an unusual phenomenon (because confession is usually held on Saturday day). Also, priests are not free therapists, and they are never going to tell you whether you or your sister is in the wrong. Your priest doesn't like either of you at this point, and you should both stop complaining to him.