Slapsgiving 3: Slappointment in Slapmarra How I Met Your Mother : Season 9 Episode 14
TV-14 CBS 23m
Aired: January 13th, 2014 @ 8:00 PM EST on CBS
In an attempt to deliver a devastating final slap to Barney, Marshall explains how he mastered the Slap of A Million Exploding Suns.
