flirting or not?

A classmate from another college, who seems to be always around wherever you are, always greets you and asks if you’re done with a requirement and even asks if you’re coming to class, is flirting or not?

A guy in a nursing uniform sits beside you in a jeepney, even if a more comfortable space is available on the other side, and keeps on leaning even if the driver didn’t hit the brakes abrupt enough to lose balance, is flirting or not?

A girl/guy across the CAL atrium, who is also part of larger group, keeps on looking even if s/he is doing something and/or talking to a friend; also gives you a final glance when s/he decides to leave for class or I don’t know what, is flirting or not?

The group in a coffee shop who traces your path, and follows you wherever you go through sight, then shares whispers, is flirting or not?

A guy in bar who throws a quick glance once and gets lost in the crowd, is again seen in a different spot and then throws another glance, but then again gets lost in the crowd, is flirting or not?

A girl who studies in another university allows her hair to be blown to your face, is flirting or not?

A person who always texts you with your name in the message, proving that it's personal, not a GM, in the morning, in the afternoon, and before sleeping, is flirting or not?

The person, who asks if you’re still a virgin, is flirting or not?

The mysterious cellphone number who texts once in a while, sometimes asking if you’re still up, is flirting or not?

The friend, who always insists on paying your fare whenever you chance upon each other, is flirting or not?

The person who takes time to stare whenever you cross against each other in AS, in FC, or in CAL, is flirting or not?

Me, noticing all of this, is flirting back or not?