Need some ideas for something to do this weekend with my gf?

We have been talking for about a month and have gone out three times. We love each other's company, have shared a lot about ourselves, and fit extremely well. So far we have just met up for lunch and conversation, been to D.C. to see the monuments and dinner, and the movies and dinner, and now I want to find something else for us to do. Anyone have any ideas??? We both live in the DC Metro area so basically anything is a go. I was thinking of heading down to Georgetown or Alexandria to see the sites, spend time and share feelings, dine, etc.