The other reply is wrong, if you and your boyfriend live together. You do not remove EIC. You claim the child for ALL tax benefits.
A common error is when unmarried parents live together, If you and the other parent live together, only one of you can claim the child for any tax benefit. The interview is confusing (it's designed for divorced parents, who are allowed to split the child). The second parent should not enter the child, at all.
You will have to mail in a paper return. He will have to file an amended return, unclaiming the child and most of the EIC and pay back most of his refund. He cannot file an amended return until his original return is fully processed (he gets his refund). You don't need to wait for that to happen, you can file now, put only by snail mail.
If you and the other parent live together, either one of you (but not both) may claim the child. You may decide between you which one will claim the child. Only if you can’t agree, do the IRS tie breaker rules apply, to see who has first choice. It may be worthwhile to prepare trial returns, both ways, to see which way the family comes out best. This tool may be useful: https://turbotax.intuit.com/tax-tools/calculators/taxcaster/?s=1.
