Mental health

My sister is dating a Jamacian guy and I only met him for 2 minutes. They almost been dating for 2 years, he hasn’t had a good first impression on me. I have mental health, ADHD anxiety stuff like that, fetal alcohol syndrome. He said something along the lines of mental health “bull$hit” that he doesn’t put up with it. One of the reasons he’s not in a rush to meet me. He said something like if we were to have dinner and he made an offensive joke and I got quiet he wouldn’t like that or put up with it. He said it’s because of how he was raised and his culture. How do I navigate this ?