Mum A is pregnant with her second child. Parents B and C offer to look after her child when she goes into labour so that her husband can be there for the birth. Her previous labour lasted 3 hours in total. When A is 39 weeks pregnant B and C announce they are going away for 4 days starting the next day - location is 4 hours drive away. This is said not as an apology just in a matter of fact type way. A feels upset and let down but manages to secure alternative childcare at the last minute in case she does go into labour during the next 5 days. She doesn't have the kind of relationship with B and C where she feels able to express her disappointment. Who is being unreasonable?