The first rule of horror is "never have sex", which considering what most people do on Valentine's Day is just a gateway to the slasher. It Follows took that up a notch in a really nice way. But most Valentine's horror is about the terror of the human condition: jealousy, possessiveness, revenge for lost or slighted love, stalker exes. And being a Highly Sensitive Person, I guess I'm concerned that people are just going to get their feelings hurt more than... the Miner from My Bloody Valentine showing up and killing people.