Guys help!! 😩

So my mom and her boyfriend have only been dating a few months. I just found out he got a work truck and van! 2 vehicles and her name is on it. Why would she have to put her name on it? Mind you before they met he lived with his sister and had no car. Is it because his credit is so screwed? She is saying no she just put her name on it to do it but that makes no sense. Help!? I don’t want her to be used. She is very vulnerable my father died a year ago.