Why do men who are in relationships go into flirt applications on Facebook?

[Woman]

This is something I just cannot understand. Could someone please enlighten me?

I'm single and straightforward. I've noticed that lots of guys are in relationships and yet go to flirt with girls in these applications. What is their problem? I even saw one who told me he is crazy about his woman he had met only 3 months ago and that he just wants to chat. For sure he didn't flirt but I still wonder what are they looking for?

[Kerry]

They are looking for a fling. It's that simple. They're bored in their relationship and trying to pick up a little something on the side, and any guy that says he's not is a liar. They go flirting, because they are fishing.

[dato]

nothing.
it's man's nature to flirt.
Flirting is where the line is drawn though.

I have a girlfriend for 11 months now and i still flirt with my female friends. Nothing's going to happen and we can be mature about it. It's fun and funny since it's always in a laughing matter.