Quote from Barney in The Rough Patch
Future Ted: [v.o.] Kids, as long as I'd known your Uncle Barney, he'd always had some pretty strong opinions on relationships. [flashback to Ted with a woman and the gang at MacLaren's:] Barney: Your girlfriend? She's your "girlfriend"? She's a girl, and a friend? How is... Do not humanize the enemy, Ted. But nice to meet you, Barney Stinson. Future Ted: And yet, in the fall of 2009, he was the one with the girlfriend. [the gang in the apartment:] Barney: Go ahead, open it. Open it, open it, open it, open it! It's my porn collection! Just kidding. That would be weird. Ted: It's your porn collection. Barney: It's my porn collection! I'm giving you my porn. Now that things are so great with Robin, I don't need it anymore. Lily: Wow. You are voluntarily... [Barney nods, Robin shakes her head] giving up your porn.