The first slap bet was between Marshall and Barney over Robin’s secret about fearing malls and was led by Lily (appointed slap bet commissioner). Barney, when learning a false truth, wrongly slaps Marshall. After they find out what the secret is, Barney is penalized for dealing out an incorrect slap. Lily allows Barney to choose between two punishment, and he decides that Marshall will get to slap him as hard as he wants five times at any moment. Barney hastily learns this was the wrong choice, for he is always fearing the everlasting suspense of Marshall’s slaps. Marshall uses his five appropriately over the years. Two of them are given at Thanksgiving, and it is renamed to “Slapsgiving”. In a future episode, Marshall gains three more slaps and uses two immediately. The final slap is given to Barney right before his and Robin’s wedding.
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