Lost

I cannot help but feel somewhat lost right now.  I have no words right now...I do not understand why this has happened.  It's not even clear to me how this happened...or why I am so upset about this.
So last night I got an alert on my phone from Facebook telling me I had a new friend request...from my sister's ex-husband who just got out of prison on October 1, 2011.  I almost crapped myself.  I call my sister to tell her who just requested me...she acted like it was so yesterdays news!  I was perplexed as to her complete and utter blase attitude about this.  I thought surely she would be just as excitable and irritated as I was...that was not happening!
She tells me (like I didn't already know or do this) to deny him and ignore him!  DUH!  Of course I did.  I denied him, an hour later or so he requested me again!  Now I am getting mad...but no one around here seems to have the same reaction I am.  Am I just crazy for reacting and feeling the way I do?
I wrote him asking him what he wants...he hasn't replied, so I am hoping he got the message...I am not dumb, I am not just going to accept him and act like nothing happened.  He's an idiot!
But, after going to church today it all makes sense as to why she wasn't as excitable as I was to the news that her ex-husband requested me.  Evidentially she already knew he had a profile...she told other people he had one, but never did she tell me!!!!!  I am so hurt it's not funny.
After all the crap that I went through in talking to the neighbor in trying to help make sure he was deported and all that, this is how she does me?!?!?!?!  I can't help but feel bitter and hurt.  Why am I the last one to know this?  Even my mom knew she thought she found his profile!  Why am I the last one to know??  What did I do?
Because of this I am feeling a bit of a disconnect from the family.  I feel like I don't belong!  I know I am being dramatic, but I can't help it.  This is the way I am feeling.  I can't help it.  I am not even wanting to celebrate the holidays with any of them.  My dad says he will talk to her, but I know he won't.  He never does.  He never gets in the middle of any of this...promises, promises...I am done.
I want to get through school as soon as possible...and get out.