One Mashgiach that I know (who is a Gadol B’Torah and B’Midos) decided that he needed to attend a mixed seating event for exactly the reason you mentioned – not causing hurt to the family. He ignored the table number on his place card and sat at the children’s table since, as he said, “I do not want to socialize with men and women, but I do not mind socializing with children”.
There are ways to do what is right and still not compromise your own values.