I remember saying CHEERIO as the pax disembarked at Glasgow one evening.
They were all Rangers supporters on a charter who had a three hour delay and had lost the match.
Quite a few of them offered to inserts various parts of the aircraft and other miscellania in my anal passage as they went down the steps. I still managed to thank them all for flying with us but it did take the edge off it!
As for Captains showing their faces quite, a few I have flown with would be better never saying anything to anyone, anwhere in any situation. In fact when i was a FO I used to wish some Captains would just stay in the cabin.