Nigerian joke

Been dating a Nigerian guy since last year September. I had him meet my mom and sister on Whatsapp video. He jokingly said that my sister looks better than me. He got yelled at by my mom. But then said that it's a Nigerian thing to joke about the sibling being better looking. Is this true?

Also he trades. I've had some accounts shut down. Trying to recover them. He says he's in love want me to marry him. We have a deep connection. I have since stopped trading and he still gives me his time. He's not working now and says it's hard to find work for him. He says he's never been this connected before. It's this a good situation?