Help me find a video?

Hello! Some months ago I happened to scroll on a video of two (I think british) theatre actors, a man and a woman, on the stage doing a dialogue between them (I think part of a play) where they discussed the importance of the author of a piece of art. I remember specifically a moment where the woman said "I love you", causing the man to stop in confusion, before explaining to him how the way she said that was different from if the same was said by his wife, or a friend, and so the same words had different meaning when said by different people.

I tried looking for the video everywhere but with no luck, could anybody help me?