No thanks, I'll wait

I looked out the window this morning to see what the weather was like, and there was a car parked outside my house with a woman sitting in it. I though nothing much of it. An hour later, when I went downstairs to eat breakfast, she was still there. Thirty minutes later I went to leave, and was unlocking my bicycle when I heard a "Sumimasen.." She asked if my housemate was at home. Judging by the presence of his motorcycle, but the fact that I had not seen him, I told her that he was probably at home, but asleep. She said thank you, I'll give him a call. And she got back in her car. I wonder what my housemate has done to warrant a stalker.