Never had any bad experience, if except at Oriental Bangkok in 2002, but we just insisted for 2 minutes and it was over.

Last experience was in August 2012. I was not traveling with my partner but with a colleague/friend in Moscow (which is not the most firendly place on earth). We had booked a room with twin beds. At check-in front desk clerk asked me with a discrete voice if we would prefer a king bed. I declined his offer explaining that my friend was not my boyfriend but I still told him that it was a nice touch and I was positively surprised.