Would this raise a red flag for you?

an acquaintance at work, added me on facebook (he has a thing for me I think although we don't really talk much). I currently live in another state from the one I grew up in, I found out he added my Best friend from elementary school which he doesn't know because she lives 3 states away. I know he is not a friend collector because he had around 160 friends, which usually friend collectors have more than that. How should I approach the situation? Would this strike you as weird?