[flashback to Robin's bedroom at 4:00 a.m.:]
Robin: Barney, are you awake? Barney?
[Robin pulls back the cover and finds a basketball where Barney's head should be. She looks over and sees him trying to climb out the window.]
Robin: Barney. This is not a one-night stand. We're dating. Come back to bed.
[A still sleepy Barney sighs, walks a few steps and collapses on to the bed]