Barney and Robin weren't initially supposed to get together.

The Chicago Tribune reported that Neil Patrick Harris and Cobie Smulders' real-life chemistry is what drove the coupling on the show. "I’d try to do little things in our scenes together where I gave her an extra look and an extra glance or would stare only at her during a whole scene just to see if anyone was noticing," Harris told The Fan Carpet of his own personal mission to get Barney and Robin together.