Reminds me of one trip back from South Africa. Sabena (a 743, I think) I was in Club upstairs so four seats across, I was in the 'A' and the other three were empty.
At Kinshasha, a Dutch family boarded and it was clear by their looking at their boarding cards, that Mum + Dad were in the 'C' and 'D' and the (apparently 17/18 year old) daughter was in 'B' next to me. The mum took one look at me and told her daughter to sit next to dad in 'C' and plonked herself next to me. I was deeply offended and took to the bottle.