It's definitely more of a combination of disgust and secondhand embarrassment. When I was 18, my mid-30s manager was clearly into me and I definitely thought he was creepy and old and everyone made fun of him behind his back. Now that I'm on the other side, it doesn't look any less pathetic. 18 year olds look like children because I'm old enough to be their parent, and the only thing I've ever felt for one is vaguely maternal affection. The idea of dating them is super gross.