Looking for a 1970s "Odd Couple" original tv series episode where Felix suggests a code phrase to warn Oscar (or vice versa) if a specific someone is about to come into the room. Oscar thinks it's a stupid phrase. I can't remember the phrase but it seems like it was three words. I dont remember who is coming. The situation then arises and Felix (or Oscar?) blurts out the phrase.
Thx for any help.

The New Year's Eve party where Oscar and Blanche break up. It happens when Felix yells "Cheese it, Oscar" when Blanche walks into the bedroom while Oscar is trying to get the young drunk woman to lie down and take a nap. Felix says "I yelled 'Cheese it, Oscar'. And Oscar gets mad because Felix yelling "Cheese it" makes it seem he was doing something bad, when he wasn't.