Three couples
Here is a crossing puzzle similar to Cannibals and missionaries. I first saw this in Averbach and Chein.
Puzzle
Three couples are on a safari, when they come to a river. The only way for them to cross is with a small rowboat which can only accommodate two people at a time. Complicating the process is the fact that the women are all the jealous type, and refuse to leave their significant other in the presence pf another woman unless she is there as well. How can the couples cross the river without any romantic strife?