Why Would You Do That?

I just want to slap a woman I work with. She was asking me if I watch House and I told her yes, I tape it every week and watch it later and that I hadn't watched Tuesday's episode. She then proceeded to tell me what happened at the end and ruin the surprise ending! I just sat here with my mouth open and when she asked what I told her what she'd done and she was like "oh, I didn't realize you hadn't watched it." She's an idiot.