Obese Friend's Coffin Lift

Listen up, buttercup. You, with your bright eyes, you should know that the joke sets you up for a positive story about weight loss with exercise and then BAM, it hits you with the sad realization that your friend is actually dead! So they worked hard to lose weight so they could fit in the coffin easier. The twist is that it is about death instead of weight loss. It's what we call 'dark' humor, you wouldn't understand because you are a moron.