The BF doesn’t seem like a terrible guy. His brother bailed on his own child so the brother is spending time with his niece and paying the child support his brother should be paying.Your SS is a-bit of an ass herself— affair with a married man and instead of going to a lawyer to get child support, she smeared everything across social media (making her look bad too). And why would his family be nice to her? She doesn’t sound like a nice person. You are 27. Your dad can’t tell anyone to stay away from you. The child’s father probably called because your BF told his bro to man up and take responsibility. Go with your gut. If you think the BF is a good person, go for it. (Although his brother is a piece of trash.)