I'm not really interested in lexical semantics. Marriage is foremost spiritual, and only became the business of government to steal money from us. I would argue he's my son, without appending the -step-. Clearly stated in OP I wasn't trying to, or interested in , trying to claim him.
@bsch4477 Thanks again for your assistance, my main concern was if the IRS would somehow consider both of our incomes as a "household" income, and not allow Mother's lower income to take advantage of EIC.
