Any chance you can get a dishwasher? You can both put dishes in it throughout the day and then you can run it at night. Your fiance will like how it prevents dishes from piling up in the sink, and you'll like how it's one daily task.

If that's not an option, consider a pair of dish racks (clean and dirty) or similar. If you can keep things organized throughout the day, that will make the kitchen cleaner. A place for everything, everything in its place.