I met one of these people a few days ago. I was boarding an ERJ behind a couple and their 5ish-year old daughter. They were going on vacation carrying a stroller and an assortment of bags and were obviously not FFs (e.g., handed the GA all their passports and boarding passes instead of just the BPs for that specific flight).

Anyway, wife seemed a little nervous about being separated on the plane and husband tried to calm her down by saying he'd ask another pax if s/he minded moving, so they could seat together. He then confirmed that his wife's seat was 17A.

Since I was on 4A, I thought the chance of being close to them and able to help was slim. But when I boarded, lo and behold, father and daughter are on 4B/C. So I immediately offered to go to the back of the plane and switch with his wife. His response: "Hell no! I've already discussed this many times with my wife."

I guess he didn't realize I'd been behind them in the boarding line. I was a little startled, but then it's none of my business how he treats his wife.