When people date a family friend or someone that was already known to the family, it makes you wonder if they had eyes for each other that entire time. Most likely.
A long time ago after a breakup, a friend/coworker of my ex pursued me. He claimed that he always thought I was too good for the ex. I thanked him and then said that I didn't feel comfortable seeing him.
In fact, during that same time I met a divorced guy who was married to a girl that went to my church during our youth. We weren't friends or anything but just saw each other around a lot and I knew her brothers. I didn't see myself in a romantic relationship with him either because of that.
I turned down a lot of relationship opportunities because I was too picky over these kind of things. A relationship would only create awkward run-ins. It just isn't for me, but other people don't mind.