HOW I MET YOUR MOTHER Season 8 Episode 15 P.S. I Love You Photos : “P.S. I Love You” —Barney uncovers the lost episode of Robin’s “Underneath the Tunes” as Robin Sparkles. Meanwhile, Marshall and Lily are concerned that Ted’s new girlfriend is a stalker, on HOW I MET YOUR MOTHER, Monday, Feb. 4 (8:00-8:30 PM, ET/PT) on the CBS Television Network. Canadian celebrities including Alan Thicke, Jason Priestley, Paul Shaffer, Alex Trebek, K.D. Lang, Steven Page, Geddy Lee and Luc Robataille guest stars as themselves. James Van Der Beek guest stars as Simon, Abby Elliot guest stars as Jeanette, Ted’s newest girlfriend, and Dave Thomas as music agent Chuck Gerusi.