Girls, What would cause a confident outgoing woman to be shy around this one guy?

She is normally very confident but around this one guy she is very shy and she smiles at him but it is a shy smile. Whenever he is nearby she goes near him but she doesn’t look at him. What causes this?

She likes the guy
Very friendly
New situation for her
Feels awkward but she wants to be friendly
Select gender and age to cast your vote:
Girls, What would cause a confident outgoing woman to be shy around this one guy?
Post Opinion