[flashback to 2006:]
Robin: [to Ted] Baby, there you are. I have spent all day thinking about all the naughty, naughty things you and I are gonna do... to cheer up Marshall.
Marshall: Like what?
Robin: Um... Uh, I'll you guys hang out, okay? Um, I'll just be waiting in the bedroom. Oh, I'm sorry. I-I didn't mean that to sound like Ted and I are gonna do a kind of thing. [suggestive mime]
Ted: Okay, okay. See you.