Woman & Their Respect

What I can never understand is a woman who feels that she needs to find herself with a man in a committed relationship. What triggers this sudden love or lust we might say? Some women feel that because a man is treating his current girlfriend with respect, love, and his heart he will do the very same for a woman who notices it all and wants the same.
I believe that many women are conniving, they will do any and everything to have said man. As I often say to my boyfriend "I trust you, its the woman I do not trust." You might be doing good but they aren't.
I don't understand why women can not respect other peoples relationships. I know they would feel the same exact way if they were in my shoes but then again some will never care. I often feel that these same women have no respect for themselves and that is why they are who they continue to be.
I've been put in situations where a random female has shown up at my boyfriends place to hangout on Christmas! Oh my right!? Or a "female friend" who will text him something inappropriate, there's even been a very funny voicemail where I swear to you the girl sounded like she was standing topless in her kitchen with the tone of voice she had.
Now the only reason I talk about woman and their corruption for other peoples relationship is because I am a woman myself and can interpret a womans mind quite well! I've never done any of these petty crimes, so don't try it hun? I don't speak from a mans perspective only because I will leave that up to a man to blog about. But you guys tell me what you think on how a woman operates? Maybe I have it ALL wrong!