Hi I got married for the 2nd time in 2013. I have kids in the previous marriage, and per divorce agreement I claim one she does the other, and I get to use EIC. I have tried to file once and it came back saying a dependant cant be on two diff tax forms. Mu ex said she put the child I claim on that he lived with her full time. Cant I do EIC? I have for years now. Can I file married sepratly to use it?

THanks in advanced