Is harmless flirting really harmless?

There's plenty of cases I know of, and I learn of more and more each day.

Story 1:  Guy has long-term girlfriend. He loves her and doesn't intend to give her up. Yet, he meets a woman he finds attractive and cannot help himself from flirting with her.

What can this lead to?

In most of the cases, the guy will not tell his flirt that he has a girlfriend. She could actually start liking him, so when she finds out that he's not really meaning anything by it, she could get hurt.

Even if he does tell his flirt he has a girlfriend, if the guy doesn't stop flirting, she could still get her hopes up.

What if the girlfriend finds out? Even if she won't act like it, she'll most definitely be hurt and that will lead to less trust in the relationship and eventual problems.

Is it really worth it?

Story 2: Guy doesn't have girlfriend and does not intend to get one. He meets a woman he finds attractive. She obviously wants more, he's not interested in more, but that doesn't stop him from flirting.

Yes, you could say that she should realize for herself that the dude is just into flirting and nothing more. But truth is that unless he stops flirting with her, if she actually likes him, there will always be a part of her that will wonder. And that part of her might keep her from opening her eyes to other guys who could offer her what she needs.

Story 3: Two people working together. They may or may not have relationships with other people. At work they flirt constantly, without actually doing anything more.

Is that really healthy?

 No matter what both of them say and how much they deny it, there's something behind that flirt. One of them is thinking about more, even if he's not saying it out loud. Things can get really awkward, because unlike with school, at work you have to show up. And when one of them wants to stop (there will hardly ever be a case where they both want to stop at the same time), the fact that they work together and are therefore in each other's faces can make things much worse than they normally would be.

I don't think there's such thing as harmless flirting. At best, even if the two involved are truly not after anything else (I don't know any such case, but assuming...), there will always be a third person that might be interested in one of them but will not make a move because of the other. There will always be an effect you cannot predict.

And besides, joking about it invites the possibility. And in many cases that leads to more. That can lead to relationship trouble, work trouble, and many other issues.

Today, in movies, magazines (that damned Cosmo!), music, everywhere, we are invited to try out the options. Semi-naked chicks tell you that flirting is fun. It doesn't have to be about anything, you can just do it without any consequences.

But there's hardly ever an action without consequences.