Almost posted this in the "most pathetic thing..." thread, but it applies to this one too, so here goes. I don't even know if it qualifies as a "relationship", but in my mind, it had potential to become one.
It was my 3rd year in college (way, way, way back in '83) and I was having a hard time meeting women. I decided to ask out a good friend's ex. (first mistake) He even suggested it cause I might get "lucky" (he did!). But I liked her too much to go out with her just to get some. We went out for the last 2 weeks of the fall semester and never did anything more than kiss/cuddle. She was always talking about her ex (not my friend, but a long-term b/f from her home town.) and how he was always putting her down, telling her she was fat (which she wasn't at all IMO) and being just a total d!ck.
As the semester ends, she's trying to decide if she want's to return after Christmas or stay in Houston where she's from. She asks what I thought she should do, and I of course say I think she should come back. She says, "well, your biased!". (well why the hell did you ask me then?

)
So, anyway, she leaves all her stuff, including her truck, in Lubbock, and I take her to the airport to fly home for Xmas, with the understanding that I would come pick her up when she returned in January. January comes. I change my work schedule so I'll be free the day she said she'd come back. On the day... I wait, and wait, and wait, and no word. I try and call her dorm room all day... nothing. Finally, I got hold of her roommate. She had come up with her dad to gather all her stuff up. She wasn't coming back. She had gotten back together with her loser boyfriend. I didn't even get a chance to say goodbye in person!
But she want's to stay friends, so we write each other letters for several months.

In one letter, she says how she want's to break up with the boyfriend. The very next, she says they're getting married.

I got an invitation to the wedding!

My friend and I thought it would be a hoot to go, just to mess with her head, but it wasn't worth it. Never heard anything from her after that. Don't know how her marriage to Mr. Wonderful turned out.
In hindsight, I'm glad she didn't come back, but it was pretty tough at the time.
