No one would say ‘yes, please’ if invited to sleep in a coffin underground

My sister-in-law and her husband Pugwash, who invited us here for a week’s sailing, are busy ordering food from the menu, providing me with an opportunity to resume, in urgent whispers, the conversation I began with my husband earlier this afternoon, when Pugwash showed us our sleeping quarters on the boat.
I am very frightened of these sleeping quarters. I am frightened of everything about them: the look of them, which is very, very small, and the feel of them, which is very, very hot.