"flirting in good humor"

Exatly.

Flirting is Flirting no matter how it’s done.

PPL do try to justify their wrong doings by different names.

No matter you are doing #2 just for fun but you don’t know other side is doing #1.

Again no matter how you justify. Once a flirting is alwaysa a flirting. #1 and #2 both are flirting and Involves a/more girl(s) and a/more boy(s).

So accoding to your definitions You are doing #2 and he is doing #1. Again same thing.

That’s what your statement explained me.