Son compartido

Am I the A hole for using my dad’s underwear to make a point about the toilet seat? I (21F) live with my parents and younger sister(13F). We have a two bedroom apartment with one bathroom (thanks to old building layouts), so all of us share it. The problem is my dad does not lift the toilet seat when he pees, and he ends up leaving splash marks on the seat. Refuses to clean after himself too. It is not just about how it looks, it also smells and makes it inconvenient for me, my sister and my m