Quote from Barney in Say Cheese
Barney: Oh, hey, remember this yoga instructor you brought to my birthday last year? [flashback to Barney's birthday at MacLaren's:] Barney: Oh, my God. You guys are not gonna believe who just came in. Don't look, don't look! Why aren't you looking? It's Slash from Guns N' Roses. All: Oh, my God! Oh, my God! Lily: Okay, okay. Group shot. Group shot! Come on! [present:] Barney: And we got it! We got a picture with Slash on my birthday. Awesome, right? Right? Robin: We were there. We know how this ends. Barney: Wrong! [Ted's date for the evening is obscuring Slash in the picture]