When does flirting go to far?

Hey guys! Most would say flirting is harmless and it's an innocent act, in most situations I would agree with that.

Usually people flirt because it is a way to show their interest in another person. But some people say that their "flirting" is often confused with mere kindness.

So when does "being nice/kind" become flirting?
Is it okay for your partner to flirt in front of you? Excessive laughing, hugging, touching, giggling, joking, compliments with someone other than your girl/guy may not be acceptable. But I think everyone flirts, and it's ok. You just don't want to flirt "to much"

I guess to answer most of these questions we would have to figure out what is the purpose of the flirting, and that is the million dollar question.