Not precisely a relationship, but I did get myself a stalker at one point. I work in retail, and a customer asked me out. We'd been joking about Baldur's Gate and Doctor Who, so even though he wasn't precisely my type, I decided to give it a shot. We went on one date where he proceeded to bring up politics, my future plans (as in marriage), and past relationships. Now, I'll be honest and say I'm not the greatest when it comes to intimacy or commitment in the first place. Especially when it's brought up on the first date. So I told him goodbye and that while he was nice, this wasn't a good time for me right now. Basically, a standard it's-not-you-it's-me speech. I figured it was polite enough and any sane man would understand it as me not wanting to see him again.
Apparently, though, he took my saying it wasn't a good time right now to mean that it would be a fine time in a week. So he called. I ignored it. So he called seven times in a row until I picked up. I told him, a little less nicely this time, I wasn't interested. He proceeds to show up at my work. I told him to leave and he did. When my shift ended, I called him to say he'd almost gotten me fired (a lie, but I hoped to guilt him into leaving me alone) and told him not to contact me again. It worked for about two weeks before he drove by my house and started calling again, asking if I'd like to go to a party and give things another shot. This time I threatened to call the police and then changed my phone number.
Fortunately I have a pretty big and aggressive dog and I don't live alone. But man oh man, this guy gave me the creeps. It was weird because I didn't take him for a perv when we went out. I just think he had zero social skills. Definitely the most horrific story I have, and while it wasn't a relationship for me, apparently the guy thought otherwise.