Future Ted: [v.o.] Oh, sorry, kids. I forgot to mention there's a bit of a back-story to this particular slap.
[flashback a few weeks earlier:]
Marshall: Oh, man. At least it landed on the mustard stain.
Barney: Don't bother. That suit is a stain. A stain on the very institution of suits. You know what tie goes with that suit? The tie at the top of a Hefty bag. A suit like that only needs one button, self-destruct.
Lily: Hey, I bought him that suit.
Barney: Where, Barfs Brothers? Men's Outhouse? Georgio Arms-Are-Not-The-Same-Lengthy? That suit is a slap in the face to all suits everywhere.