Hey! I’m old! I remember seeing this commercial live on TV. I remember being confused about whether they were sibling or bf/gf. Had to see it a few more times before I was sure they were written as siblings. Still got a weird vibe from it. Years later when I first heard of the “Folgers incest commercial” I knew exactly what was being talked about. This was definitely something at the time people were talking about.
I get what you're saying. I personally think the commercial's odd but get way more creeped out by the internet's unironic obsession with incest media (incest porn, incest fan-fic, incest memes).
True, people laugh at this but then cum non-stop to step-son getting seduced by step-mom and step-sister getting jealous and deciding to make it a threesome and then dad comes home and bangs all of them in the ass porn.
We all get what's going on. It's weird. No story is better at that point.