It takes them 10 days to get there and when they do, horror of horrors, they find they have left the bottle opener.
Jim and Ray ask Geoff to fetch it. Geoff says "No way, do you think I'm stupid? By the time I get back you will have eaten all the sandwiches."
Jim and Ray promise not to eat them, so Geoff agrees to go.
10 days pass and Geoff has still not returned. 20 days pass and still no Geoff. Needless to say by this time Jim and Ray are starving but still keep to their promise not to eat the sandwiches.
25 days pass and Jim and Ray agree if they don't eat the sandwiches they will starve.
Biting into their first mouthful in 25 days they start to eat the sandwiches when .......
Geoff jumps out from behind a rock shouting "You ********, I knew it, I knew you'd eat the sandwiches. Well you can forget about me going back for the bottle opener now."