Question for anyone in the know.

H has always done our income tax filing jointly. I have sent him the question whether we're going to file jointly or separately this year. I know that still being legally married we could do that. If he says he wants to file separately can I claim our 2 younger children on my income tax even though he pays child support? My paycheck is used to pay mortgage, utilities, taxes, insurance and maintain the residence. He does buy the girls their extras, clothes, toys over and beyond C/S.

Thanks