While the foreshadowing they show during the episode was never actually on camera, there were actually tons of hints about Jeff and Britta sleeping together in Cooperative Calligraphy.
- "Gwennifer" is an obviously fake name.
- When Jeff "calls" "Gwennifer," he doesn't even hang up the phone before throwing it on the desk.
- Most importantly, this exchange:
Britta: "This Gwennifer must be real special. Don’t you usually wear the stripey turquoise Beetlejuice numbers? "
Abed: "What does she mean by usually?"
--
"One toot on this whistle will take you to a far away land."
-Toad, SMB3