Is this a red flag?

I met someone online. I used bumble and we have been on a couple dates. He told me he has a girl best friend he's extremely close with. They game together. I met her tonight and I'm not sure if this is flirting or just friendly banter. She was saying how she keeps getting those USPS text scams and he said he can't believe people fall for those. She goes "Didn't someone on Facebook scam you out of almost $1,000." He flails back laughing and says "You. Absolute. Bitch! We don't bring that up!" They were both laughing. Someone said they were gonna fix his car for him and then didn't. They just took his money and blocked him. I don't really have friends at all. No male or female friends. So I'm not sure if this is just friendly banter.