She's not teasing bc She's nervous to be around you. She might have some feelings! Just try not to be creepy about it. Don't stare, maybe talk to her and try to make her laugh. Don't tease her tho. I mean no punches, names, just be casual. And don't push it too far. If you have a good friendship for a few years, start making some plans! Dates, ice cream, etc. Hope I helped!!
~Outstanding Owl ~
Ps, sorry this is a girl.