Robin: I didn't think I was gonna think about it, but then, I thought about it.
[flashback to the whole gang at MacLaren's:]
Barney: Oh, this pilates instructor was off the charts. Picture Robin, but younger. And bigger boobs. Maybe not bigger, but more shapely, and bigger.
Anita: [answers the phone] Hello?
Barney: I get her up against the StairMaster, and we...
Robin: [on the phone] Do it.
Barney: Spoilers! Anyway, we do it.
Anita: It's done.