Season 3 "Ordinary People", two distinct window scenes. One towards the beginning where Clark/Superman is leaving and says "..hehe. Bet?", and the second one at the end when he brings Lois flowers and offers to show her a receipt. Windows shown clearly opening outward with knobs for Lois to pull them inward to close.

Clark: "Lois, you know, I really hope someday that you learn, that sometimes what it seems like people are doing isn't what they're really doing."
Lois: "What are you, a fortune cookie?"