What did my best friend mean?

My best friend and I went to Vegas earlier this week. We were in the hotel room reading one of my magazines, which had an infographic detailing the most concentrated areas of cheaters, according to a website that enables married people to cheat.

One of the top cities was in a state that my boyfriend and I would like to move to in a few years. My friend's relationship with my boyfriend is good, and she approves of him.

But when we were looking at it, she said, "This state has a lot of cheaters in it. Don't you want to move there?"

I said yes but that I have my boyfriend and don't have a reason to think he'd cheat.

(First we're moving to the city where she lives then will move away after a few years to begin a family together. She's happy that we're moving close to her but wants us to stay.)

Then she said that "well, some people could be converts."

My boyfriend isn't a cheater. Why'd she say that? I don't think they have done anything.