Hi Jennifer,
Walt Disney World has so much wonderful dining! Let me offer you a few suggestions for your special meal.
I have a couple of thoughts for dining locations in theme parks that have seafood. At Epcot, you could try
Coral Reef Restaurant, which not only features seafood on the menu, but also provides a view into an amazing coral reef through huge windows! Of the restaurants I am going to recommend, this one is probably the one I think of the least as specific for couples, but you could certainly enjoy a meal there. Another possibility in a theme park is
Tiffins at Disney's Animal Kingdom. This restaurant is newer and the flavors tend toward the exotic, which I love. Recently I dined there and we enjoyed, among other items, the octopus appetizer. This restaurant also features a whole fish on the menu.
Though you were ideally looking for dining in a theme park, I have a couple of ideas that are easily accessible from theme parks. These both feature seafood and I have enjoyed an evening out with my husband at each. From Magic Kingdom, you can hop onto a boat or the monorail for a quick ride to
Narcoossee's, which is a lovely restaurant right on the water of Seven Seas Lagoon at Disney's Grand Floridian Resort & Spa. From Epcot or Disney's Hollywood Studios, you could take a quick walk or boat ride to
Flying Fish at Disney's BoardWalk. The seafood focus is right in their name!
The menus from all of these restaurants are available at the websites that I linked. Please let us know if you have any further questions, Jennifer!