Stealing glances at him when you think he's not looking but when he is looking your way you qucikly look away and blush, leaving him perplexed
Whenever you see him in the hallways, you asking him how he is which he always responds with something along the lines of, "I am functioning properly."
Asking him to go to the holodeck with you during your off hours
Him being clueless as to why you're always complimenting him and asking to hang out with him
Him defending your opinion when Picard or Riker asks for it by saying stuff like "The data would seem conclusive" or "It does seem like the likely conclusion, sir"
Him starting to develop feelings for you but being very confused by them, which ends in him asking Commander Riker about them
Riker telling Data he's seen you gazing at him with googly eyes which Data gets very confused about. He's all cute and like "Googly eyes, sir?"
You getting very flustered and shy when Data confronts you about your behavior
Riker setting the two of you up on a date on the holodeck which you "get mad" at him for when in reality you're over the moon