what is up with men and this issue they have with clinginess?

the word clingy is like an all incompassing word that means what exactly
I don't even think men know
it was handed down from generation to fucking generation and now they just throw it around as simply as they say the L word

I don't know what to say
its been a while since I've been on this thing
I doubt if anyone really even reads my blogs anymore
but this is something i just had to get off my chest

why do men have this incessant need to be unfaithful?
I don't get it
I really don't
I mean I think I'm a nice girl
I'm intelligent, half-way decent looking
I don't think I'm alot of stress
but yet................almost all of my relationships ended because the male in the relationship was seemingly unsatisfied and had to sow his oats in some greener pasture some where
what the fuck is that?
and don't get me wrong but I abhor all forms of unfaithfulness
take for example so called "harmless" flirting
I just don't understand why you have to flirt with someone else when you have a perfectly good woman who cares about you
why is that?
I mean yes women do shite too
but I have to say on record that I have never cheated on any of my boyfriends
and I wouldn't want to
I don't understand I just can fucking understand
its getting to the point now where I have no faith in men at all
none
I expect that a man will cheat on me
I expect that he will lie to me
its to the point where I don't believe anything they say to me
and once a person lies to you
you never know when they were telling the truth and when they started lying

someone please help me to understand becuz I think that I'm fighting a losing battle here
and I just don't understand
I feel like I'm sinking under water and turning into a very sour, bitter, distrustful woman
I don't like it
I don't like it at all