Oysters are the ultimate first date food. They're low in calories and help reduce inflammation so you won't feel uncomfortably full once you've downed a few. They come in their own little plates so messes are at a minimum.
Oysters are a casual food that can be assembled in seconds, so you won't be stuck waiting for the food for too long. It's more a snack that you can enjoy over drinks, so it's a good compromise if you don't want to commit to a full dinner.