For 2024, your boyfriend can claim you assuming you live together the entire year, and your taxable income is less than $5050. You would not be required to file a return if your income is that low, but if you did for some reason, you must check the box on your return that says "someone else can claim me as a dependent" and you can't claim any deductions, credits, or dependents. Your spouse (if you are still married as of 12/31/24) should not attempt to file as married filing jointly, since I assume you would not give permission for that.
If your boyfriend is the biological father of your 2 children, he can claim the children as dependents, even if you break up and move out, because the children lived in his home for more than half the year.
