Why didn't my boyfriend want me to say hi to his neighbor which is a girl and I happen to know her?

I find this very weird, but I came from vacation I (27 y/o) was out of the country for like two months, so I came back and I went out with my boyfriend (36y/o) yesterday and before we were getting read for him to bring me back home , he told he did not want me to say ’‘hello’’ to his front house neighbor which happens to be a girl and her family, and in fact I happen to know her from the gym that I used to go, anyway I asked him why? And he said because he had parked the car close to her house the other days and they were looking at him in a weird attitude manner since he is a foreigner he has these ’‘ideas’’, and when we were walking out of his house he told me to walk towards the front of the car and not behind the car (which was closer to her since she was outside chatting with some other girl) I wonder if he has cheated with her because I find it so weird that he did not want me to say ’‘hello’’ to her, he was like ’’ I don’t want you to say ’‘hello’’ to those people’’ The real reason I don’t know,,,, I mean they are poor and we live in the Caribbean, but I still find it Awkward and weird, what do you think? I would love to see her one day and ask her stuff, but I don’t have her mobile, neither her Facebook, but I would love to.