FACT: i found a new icon on our computer; it was itunes. well i clicked it and it went to a page of videos well some of them I recognized some that i took but there was a new 23 minute video saved on there so I clicked it. It was a guys saying how much he missed my mom and the next few minutes he was going to "think" about her. He got up and left the screen and then he came back and was naked I skipped more and stopped it he was making himself "hard" saying that if they had sex it would be hot and passionate. And at that point I clicked out and just BROKE DOWN! what am I supposed to do!!!            

hmm.

I suppose if I was in a similar situation I would confront my mom.  I would make sure my dad was out..for a while, and I would bring her to the computer and start playing the video.  She has a right to know that you know.  This is probably going to be terribly embarrassing for both you and her, but once you get past the embarrassment, it's possible that you will get some explanations.  Hopefully these videos were given to your mom BEFORE she got back together with your dad.  

Even though this is probably really awkward for you, its important that you don't judge her.  She's a grown woman, and what she does on her own accord is her own business.(assuming she isn't cheating on your dad).  Try and be a little open minded, and make her as comfortable as possible while she is explaining this.

So usually when I say this I only halfway mean it, but honestly, this time i mean it 100%.  PLEASE be sure to let me know how this situation works out for you.  I'm very interested.

Good luck with your family! :D

-------
:)