Help w my 5 year old

So, my husband and I divorced in November the kids and I moved and they started a new school. They are 4, a girl and 5, a boy. Nothing has changed over e last several months and all of a sudden my 5 uear old so is telling me that he does t loveme, doesn't want to. E with me, only wants to live with his dad and doesnt love his sister. This is really stra ge behavior and if I were to ask my ex about it nodobut he would blame it on me. I have explained to my son that I love him, want him, need him and so does his sister. That we want him to be happy and have fun with both mommy and daddy, I have to,d him all the time that he doesnthve to choose and that I want him to have fun in both places. He goes for hours doing great and then turns in us. Says that he doesn't love his sister or want to. E with me, that he just wants to be with his dad. That is not possible based on my want for him to be with me and because his dad is not in a position to have them more than a couple days a weeks after school and over the weekend.
I have tried to encourage him to talk, he will, he asks me ifI miss his dad, I tell him that I can call him anytime and that I am so happy that we both made both of you. I know that I can't stop his dad from saying things, that he will continue to blame me for all of the issues since I was the one who left. Help.

[Sandman2]

   Very good points by specialmom.  
Another thing that I think will help is that there are several wonderful sets of books aimed at the 4 to 7 year old kids to help them with expressing their emotions.  They are meant to be read aloud to them (which also is a nice bonding time).  You can find them here and then if you scroll down you will see the different titles.  I am sure that you will be able to find some beneficial ones.  And by the way, theses books are meant to be read many times and talked about.  They also are helpful in that they give you and your children a common vocabulary.  The place you can find the books is - http://www.amazon.com/When-Feel-about-Myself-Books/dp/0807589012/ref=pd_sim_b_45
    Hope this helps!

[specialmom]

Oh, this is so hard.  I'm sorry about this.  

Kids of 5 have limited ability to really share their emotions.  He's clearly distressed by the changes.  He's probably sad. He may even be a little bit angry about it.  Really, those are normal reactions.  

And you are probably his 'safe' person.  What that means is that he can say something hurtful to you to express his hurt inside and deep down he knows you'll always love him.  He reserves his worst behavior for you because he has your unconditional love.  Does that make sense?

I would say to him, "honey, I know this hurts.  Wish i could make it better.  Mom and Dad will always love you."  Give him  hugs at these times.  Give him support and comfort.

I think this is just your little boy's way of telling you this hurts.  

It would be so beneficial if you and his dad could get on the same page and have a cordial relationship for the sake of these kiddos.  Ah, in a perfect world . . .
peace and luck

[Sandman2]

   Very good points by specialmom.  
Another thing that I think will help is that there are several wonderful sets of books aimed at the 4 to 7 year old kids to help them with expressing their emotions.  They are meant to be read aloud to them (which also is a nice bonding time).  You can find them here and then if you scroll down you will see the different titles.  I am sure that you will be able to find some beneficial ones.  And by the way, theses books are meant to be read many times and talked about.  They also are helpful in that they give you and your children a common vocabulary.  The place you can find the books is - http://www.amazon.com/When-Feel-about-Myself-Books/dp/0807589012/ref=pd_sim_b_45
    Hope this helps!