to have screwed up or failed at a task, usually spectacularly or with disastrous results. Said failure can involve lack of effort or lack of competence and usually both. Vulgarization of "screwed the pooch."
Bridegroom: dude the whole stripper-in-a-cake thing is more fun when she's not 74 years old and narcoleptic
Best man: yeah i really fucked the dog on that one didn't i