How much contact is appropriate after a break-up?

Going forward, she requested that I let her know when I start dating someone else because she thinks that will make it easier for her to get over me. This is weird and inappropriate behavior. You do not owe her a running debriefing of your love life because she would appreciate that for whatever weird and inappropriate reason she has. If no-contact-permanently works for you, then that is what you should do. The terms of the breakup isn't something both parties have to consent to.

I also think you fucked with her head a bit by breaking up with her and going "no contact" the very next day. I bet that was shocking and traumatic for her. People often "get stuck" in shocking and traumatic moments. I don't know how you help her now. Don't go overboard here! What's done is done. Just... Maybe be a little less abrupt next time? Provide a little warning that you are going to do the "no contact" thing, as well. It's something to think about for next time.

You dumped her for good reasons and then went cold turkey on her. As someone who was engaged recently and had this happen to her, let me tell you: it was the worst experience of my life to discover that my fiancé was not in love with me and that he had no interest in being with me anymore. You know what the worst part was? He became totally paternalistic and started checking up on me regularly to make sure I hadn't killed myself in grief. Oh yes! That was charming. I would have rathered he dropped off the face of the earth or given me a second chance but none of that I between guilty shit. That's what she's dealing with right now: the reality of what you did, and the tug of seeing you again and wondering why it just can't start back up again. Unless you didn't give her a concrete reason for why you ended the engagement the first time around, you need to tell her point blank, "Contact is too difficult and it is interfering with our ability to move on. We must go our separate ways completely. I wish you well, and I will treasure the times we had together, but we are not compatible and I cannot remain in contact with you." Have some sympathy for the ex in this situation, people. Being dumped while engaged is devastating. She's not crazy -- she's trying to figure out what the hell happened to ruin her once-in-progress marriage. OP, you staying in contact equals shitty and manipulative and self-serving. Stay away.

Her being "very worried" is manipulative, and probably mostly a lie. As is the thing about wanting to know if you're seeing someone. Or her partner, the man she was planning on marrying because they were engaged, suddenly left her and stopped speaking with her. If that happened to me, I'd be pretty worried about my ex, too. It sounds like this was sort of a surprise to her, and she is probably trying to understand what happened. That's also why she wants to know if there's someone else involved: this kind of event is often (not always) precipitated by infidelity, and she's probably trying to make meaning of this very shocking thing that happened. Planning to spend the rest of your life with someone and then having yourself cut out of their life entirely is a very surprising and scary thing. She's not being manipulative as much as she's trying to figure this all out and move on.

Did you guys talk about the impending breakup before you broke up, so she was more emotionally prepared, or did you just say, "hey, this isn't working for me, bye". I think that has a lot to do with how the after break up plays out. If you just left, you probably left her in shock, which makes going forward so much harder for her to process and keeps the hope alive. She still has hope if she wants to know when you start dating someone else. It might be that there wasn't any real closure (which is why I love the idea of going to a relationship counselor to break up). This being said, what she wants, contact, is probably going to be the hardest for her, so I do, personally, think the no contact is for the best. But it should have been discussed a bit (which it doesn't sound like it was, I could be wrong) so she knew what to expect going into the future.

There's a big difference between going no-contact on a former GF and someone who was a would-be life partner. Big difference. Context is a very important thing here. She thought she was going to spend the rest of her life with you. And then nothing. That is a big thing, particularly for someone so young. As jbenben said, it's traumatic. But as a separate issue, you don't owe her any information about who you're dating. And you don't really owe her any further communication if it's difficult for you. But I would have a great deal of compassion here for your ex-fiancee - going no-contact on someone you were going to marry (unless it's an abusive situation) is just not a thing to do.

May I gently suggest, then, that if you are already over what happened after only 4 months, the degree to which the your ex is feeling jilted is now extremely understandable and her behavior not at all that surprising. Do not reveal that reality to her if you do somehow wind up in contact with her again unintentionally, because that will hurt her more than you can possibly imagine. And obviously, don't propose to anybody you could conceivavbly get over in just 4 months, but that kind of goes without saying. Hopefully both of you will find better matches in the future.

I asked http://ask.metafilter.com/225030/How-long-should-we-wait-before-trying-to-be-friends about how long the no-contact period should be, you might find it helpful. http://ask.metafilter.com/225030/How-long-should-we-wait-before-trying-to-be-friends#3254946 was the most helpful answer for me: "You've got a date? Hope you have fun!" "Oh you're engaged! so awesome!" "You and Jessica are having a baby?! when's the shower?" When uttering any these sentences would have the same weight with your ex as anyone else: then you can start talking. When all of them do: then you can start being real friends. That's my rule of thumb.

I was in a 3 year relationship. We lived together, but then had to live on different coasts because we were both in the Navy and got orders to different places 1.5 years in. At the 3 year mark, when we now were stationed only 2 hours away from each other, he pulled what you did... just called it off, cut off contact, and basically disappeared. I coulda used an explanation. I coulda used some closure. He didn't act like an adult, he didn't discuss issues or problems, he just cut off all contact. I suspect that's what your ex is hoping for... for some sort of REASONING as to what happened and why. Oh and my ex? EIGHT years later he tried to reach out to me, like it was something from a long time ago that we'd just grown and learned from. He hurt me, BAD, with his silence. Yes, I've moved on, but he's still a jerk. And I'll have nothing to do with him. My advice to you would be to man up and quit jerking around with people's emotions. Just be honest and communicate. I'd rather hear an EXPLANATION for what was wrong and why the relationship wasn't going to work than him just leaving me in the dark eternally wondering, while I cried to my mom on the phone, wondering what was wrong with me.