That's true, I'm very reluctant to repeat scenes in most games unless the game makes it very obvious that results will be different, because it feels like I'm doing the same wrong thing multiple times. A friend of mine who made RPG Maker games once had to tell me I had to talk to each NPC 10 times (!) to advance the plot, and she was so proud of how she wrote 10 lines of dialogue for each NPC in her game.
Maybe have the game tell the player that doing Morticia 3 times will unlock the next event.