Threads like this one coinciding with (non)events in my personal life* have created within me the perfect storm of curiousity 
So, were you dating someone else when you met the one you love? If so, did meeting “the one” cause/contribute towards your break up, or did it die a natural, unrelated death?
Yes, yes I was. I was dating him in college and they were roomies.
After him and I broke up, it was natural.
Check back with me in a year or so.
No.
I was completely single when I first met Mrs. D… and I was single again when we ran into each other again in a college class… and I was still single when we ran into each other again in another college and finally started dating.
It was amazing how life just kept making us bump into each other.
Neither of us was strictly “dating someone else,” but…
[ul]
[li]She broke up with her boyfriend when I invited her to visit Seattle[/li][li]Once she was here, I ended the on-again-off-again cow-orker fling.[/li][/ul]
Also, uh, rereading the OP…when we actually *met *we were both single, although I was in hot pursuit of someone else. Never let it be said I know what I’m doing (apart from marrying shE. Thorp. That was right on.)
I met my husband when I was unattached, but when he made his feelings and intentions clear I was with another guy - actually I was living with the other guy, as I had started the year homeless (looong story). Without getting into gritty details, I spent a little while getting my confused self worked out and broke it off with the other guy. I moved in with my husband more or less directly, and have been under the same roof with him for seven years now.
Yep. Married now and wonder what shes doing …
I was dating TWO someone elses, and one had proposed to me. I broke off a longish relationship, announced I was playing the field for awhile, and went out on a date with a waiter. The date ended badly, but I met the guitarist with the house band, and started seeing him. Then ran into an old flame. Was dating the old flame and the guitarist, both very casually. Then my Mother set me up on a blind date - the blind date was Friday. The old flame proposed to me on Saturday. I asked for a little time, then went out with the blind date on Wednesday. Thursday morning I called the old flame and declined his proposal. Had a date planned Friday with the guitarist, and called him to break the date.
Moved in with the blind date about 60 days later, and married him the following year. We’ll be married 18 years this summer.
I met my husband while I was engaged to another man. However, at that point in time, I had no interest in him, since I thought I had “the one”. Until “the one” ran off with another woman.
Two is better than one, anyway. 
I’d been in a relationship for a few years, which for the previous two years had been a long-distance relationship where we only saw each other in the summer and on the big holidays you’d go home from college for. He’d been gradually getting harder to contact and not writing as many letters, but he always blamed that on being so busy at college. Meanwhile, my second year of college starts and I meet a neat guy who hits on me then I tell him I’m dating someone. I’m also talking with a mutual male friend about our respective dating partners and whether he and I should/shouldn’t break up with them. Unbeknownst to me he’s feeding this info to the other guy, who’s continuing to be friends with me but isn’t above acting mildly flirty. He knows there’s a shot for him yet, after all, but in my mind I’m thinking “wow, he’s so nice and such a good friend, and mm, wouldn’t it be neat if…”
Anyway, I finally got frustrated enough with my then-boyfriend’s emotional distance that I broke up with him and rebounded with the new guy. (Technically I was going to break up in person but I got a “yeah, so, I’m gonna spend Thanksgiving with my roommate’s parents, see ya later” note from the then-BF, so I figured screw that, and IIRC started up with the new guy before writing the “Dear Jerk” letter. New guy knew the situation at the time.) Today, this rebound guy is my husband of several years and my best friend as well.
I think having this “option” available hastened my decision. I probably would have been a doormat for quite some time if I didn’t see this handsome, interesting guy right there. I believed so hard that I had to be understanding and caring that I bought all of the “I’m so busy” excuses for not writing, for getting off the phone quickly, etc., when from his reply letter it turns out he was trying emotional neglect as the “easy” way out of breaking up, and apologized for the pain he had caused as a result.
I was dating two men when I met my husband. The “real” boyfriend and I were in an off again stage, but hadn’t officially ended it (although we weren’t speaking at the time I met my sweet baboo). I was also having an affair with my old boss, a much older married man who loved me and whom I loved, but who really was in no position to be with me full-time. Since neither relationship was really appropriate for a nice young woman like me, my co-workers fixed me up with the old friend of the fiance of one of them. The day after our first meeting, I saw the old boss and we spent the night together, but he told me then he knew I was going to marry this guy (even though I wasn’t overly enthused) and he was right. The other guy started calling me trying to get back together very soon after and I ended up sending him a Dear John letter because he was so pathetic I couldn’t bring myself to tell him I’d found someone else over the phone.
Nope. I had gotten out of a very bad relationship about a year before I started chatting with my future wife online. By the time we finally met IRL, I knew she was the one. When we were first getting to know one another, she was in the process of breaking up with her current boyfried, so the timing was perfect.
Not my story, but my boss’s. He was doing the casually-serious-dating thing with three different women at the time, seeing how things would pan out. Then he took a night class, met someone else, and the next day, broke it off with all three of them. It was another year or so before he started actually dating the “someone else”, but they’ve been happily married for about five years now and he doesn’t regret a minute of the wait.
As he says, sometimes you just know.
Yes. One of his best friends. Yikes.
I was dating a few guys casually, not looking for anything serious, when serious fell into my lap.
Married now, always wondered what happened to Rich. He was a very nice guy and deserved a great girl. I hope he is happy.
Yes, though I didn’t know it at the time. When I first met my wife I was dating a different girl, pretty seriously. Future-wife and I hit it off well, but we had different, barely-overlapping circles of friends and didn’t run into each other all that often. Fast forward about a year-- My relationship with the other girl had ended, circumstances changed, and I started seeing a lot more of future-wife, and before too long we really hit it off.
Short answer:
No, I was not dating someone else when I met “the one.”
Long answer:
It was a long time before “the one” (or, “the one who was to be ‘the one’”) and I got romantic. When we first met, I wasn’t dating anyone, and he was dating someone casually. Then, I started dating someone casually, and at some point, he broke up with his casual girlfriend (mostly amicably). Later, I stopped dating my casual boyfriend (mostly amicably). Then neither of us dated anybody for quite a while, and then we did start dating each other, but not casually. 
The whole process took years.
Maybe it was subconscious, but I really don’t think that either of our break-ups with the casual dates was related to the other. As I recall, he and his casual girlfriend broke up because he wanted their relationship to be more serious, and she did not. So wow, things could have gone a whole different way if she had a different response.
Going back 11 years, every Wednesday night during the Summer was spent at Jenkinson’s watching The Nerds perform. There was a girl who went every week as well who I was incredibly hot for, but who was way out of my league. We’d talk and dance a bit every week, but there was no way I was going to embarass myself by asking her out.
Then one week, she said to me “You know, you and I really need to go out on a date sometime”. My resonse was something along the lines of “Guuhhhh, duh duoi…”.
When I regained composure, I agreed that that sounded like a fine idea indeed, and that we should do something that Friday. She already had my phone number, so we decided that she would give me a call on Friday afternoon, and we’d figure out plans for that evening.
Friday came, Friday went – no phone call. That, in a word, sucked.
The next day I met my wife.* Damn good thing I never got that phone call. 
*To those of you who know the whole story, yes, I know we had actually met years before. But that was the day we started dating…“met” just works better there.
Yes. I was dating a friend of my brother for the summer (had recently broken up with a live in boyfriend - my son and I were hanging out with my brother for the summer up by Busse Woods with him and the other boat people) and went to the bar after work one day and by chance met the future husband. Broke up with brother’s friend right quick, and husband moved in. That was 11 years ago. We’ve been married 5.
Nope, I had been single for over 2 years when we met.
I was dating someone who I knew from a BBS. I ended up meeting a few of his friends online, then IRL at a party. One of his friends, Asimovian, was utterly bizzare and pushy, but somehow endearing. We became close friends. I knew he was interested in me, but he wasn’t my type and I didn’t want to mess up our friendship. A year later, we started dating and we’ve been married for almost 8 years.
So yes, I was dating someone when I met “the one,” but I didn’t figure that out for quite a while!