Some people are a bit too
free spirited and lack the honesty to live that life without hurting others. It's one thing to throw yourself at guys, it's another to get involved with them and not being honest about how you really are.
If you want to live that kind of life then you should be open and honest with the people you're about to get involved with. What might be a fun fling for you might hurt them pretty bad for days/weeks/months depending on the person.
I can't help but to look down on that kind of life style, too much risk of hurting others. I hate hurting people, whatever the reason it is, I can't stand it and the guilt overwhelms me. If both partners are okay with a fling then by all means, but to hook up with someone you've just met without telling them anything about you or the sort will just lead to you hurting them eventually.
That's just my opinion anyways~