I've more or less been lurking here for about year or so and after today I'm pretty sure Im starting to figure this out.

So earlier today I was on my way to class and had just gotten off the metro at the Atocha Renfe station in Madrid so I could hop on my train to get to campus and today it is really freaking cold outside.

Right after I got off the metro there was this cute blonde girl walking just to my side who was wearing knee high boots and shorts. When I saw her my thought process wasn't much more than "she's kind of cute, I kinda of want to talk to her". So I walked over to her and said. "sabes que hace muy frío, verdad". She looked at me with a puzzled look on her face and said "what?". I briefly put my hand on her shoulder and said "you know it's really cold out right?". She giggled and said that she was fine, and I made a quip about how she looked more like an American than other girl in the place. She laughed and we joked about why I started out speaking spanish to her if I knew she was an American. By this time we were right by my train line so i told her "well that's my train, don't freeze to death". She laugh and said bye.

The whole interaction was really short, no more than 5 minutes and the whole time I was just having fun. It wasn't untill I got on my train that realized she might have been into me. So thank you seddit, I think I'm starting to figure this out.