I'm confused.
Why did no one mention the single best reason for House to brush off Stacy? Which is to say THE BITCH IS A BAD BET!!!
One needn't be a slasher to see that this is a fair-weather lover. She left House when he hit a physical rough patch and was getting ready to do it to Mark. Who needs that? Not House, not Mark, not anyone.
Still, until that farcical last scene where they have Wilson pretending he's sorry Stacy is gone, was he not the very picture of jealousy? And delight that he has his House all to himself? I was certainly the picture of glee.