Ancestry Dot Con

I'm a single woman in my mid-30s with an older half brother I haven't seen in 20 years. He started calling me several years ago, and we speak sporadically (always instigated by him). He's married and refers to me as the aunt to his four children (whom I've never met). Recently, he asked whether they could all stay with me for a while. On the next call, he asked to borrow money. I have yet to give him answers. I can't help but suspect he just intended to use me all along. Is there a way to figure...