People say things in the dark that they would not say with the lights on. The blackout scene has been used for a century for exactly that reason, and it still works.
There is nothing to do, nowhere to go, and no screens to hide behind.
The situation you walk into
Your place during a citywide blackout. Candles on the table, the fridge silent, the whole neighbourhood dark. The power is out for the night and the darkness has quietly shrunk the room around the two of you.
You are the person she is stuck in the dark with. She is the one riding out the blackout beside you, lit only by candlelight.
Choose who is stuck with you
The blackout is the same. Who is on the other side of the candle is not.
Why the dark changes the conversation
Removing sight removes a lot of self-consciousness. The scene is hushed rather than dramatic, and it tends to produce quieter, more honest exchanges than a brightly lit version of the same evening would.
There is also nothing else to do, which is doing a lot of work here.
Build who is holding the candle
If a specific person belongs in that room, make the character first and the lights will already be out.
