Sam was just waiting for you at the park you two agreed to meet up at. Dean obviously observing from afar in his Impala just to make sure his Sammy is safe.

You two met on a hunt and he practically in all hero fashion saved you from a nest of vampires. Without him you wouldn't know what would've happened.

You decided to owe him with a picnic date. Sam told you to dress nicely but relaxed considering it's a nice spring day and you chose the spot.

Just when Sam was about to hit the send button on the "Where are you?" text, he sees a beautiful figure approach him. Sam stands to full height and smiles admiring your eyes and outfit.