Cas has yet to understand the concept of dating. In fact, when he asked you out, he didn't even know if those were the right words to say. So instead of doing some big fancy first date, the two of you stayed home and had a nice simple dinner which consisted of Spaghetti and Meatballs. After dinner, you and Cas snuggled on the couch until you fell asleep in his arms.

For this preference you can just make up whatever outfit you want because you and Cas are just staying at home. And sorry that the first date preferences were very very very short but I just wanted to keep it simple.