What does it mean when a guy texts back immediately?

If he texts you back immediately (ie, within a few minutes). Depending on how you feel about him, he could be someone who has no job or hobbies or friends or goals because hes always around like hes waiting for you to text him, or hes a guy who is like, Yay! Kristin texted.

What does it mean if he never texts first but replies?

If he doesnt text first, but always replies, he might be feeling a bit intimidated by you. If theyve never had a girl be brave enough to double text or message them first, they might not be sure how to handle it. Theyre likely a bit nervous about how to play things and want to make sure they impress you.