I just got dumped for the same reason again, so bear with me, there is a legitimate question here, but I need to describe the situation(s), and that's a bit of a slog.

More than 8 years ago, my girlfriend was the woman of my dreams and she was just as in love with me. Right around the 1 year mark, we started having the conversations that you naturally have - do you want marriage, do you want kids? My answer is maybe to the first and definitely no to the second. I'm open to adoption, but I have severe moral dilemmas with bringing new life into this world. She disagreed, so despite being madly in love we part ways. That sucked.

I've kept in touch with her, met up with her in the spring of 2011. It was the first time we'd both been single, we hooked up, she still loves me, I still love her, same issue still stands. She shared with me how tough it had been dating knowing that she had to eventually inform some poor schmuck that she was still in love with me, but she'd been figuring that out and navigating. The same way I had. It sucks.

I met my most recent girlfriend shortly after that. We fall in love, she understands, and I am clear from the first f***ing date that I don't want kids. Marriage, for me is a formality of an already intact arrangement - not off the table, but doesn't carry the same weight with it as it does for some. For me that commitment comes earlier.

We celebrated our one year anniversary on Oct. 15. She turned 29 soon after, and went from hating kids to knowing she wanted them in her future. She grew distant, reserved, and we broke up last week. Because she wants kids, and a wedding.

In talking this through with friends I keep hitting a brick wall. That it doesn't matter that we spent a year with the same expectations. She has an inviolate right to change her mind on a whim about these major life things, and there is nothing to be done about that. I, mostly, agree with that. I mean, you can't be a controlling jerk about these things, but seriously? WTF? Look at it from my perspective. I got burned this way once. I communicated it clearly from early on, re-affirmed it many times, and suddenly BAM! Same thing.

Now, two does not make a huge sample size, I've dated a lot more, just haven't gotten as serious with others. You obviously can't guarantee people won't change their minds, and I know I'll find someone eventually. But in the meantime, do I really need to keep burning more than a year at a pop just to, I don't know?, help someone through a process of self discovery just to wind up getting dumped? Is there a way I could be going about this better?

Why is adoption anathema to some people unless there is no other option?

Is there any way to make this process easier? I little safer for me?

And, seriously, is there just a universally accepted notion that if I'm the one not wanting the traditional relationship progression, that I'm in the wrong? My friends who, dammit, should be supporting me, are largely taking up her case and trying to convince me to change my mind about kids. What's up with that?

tl;dr How can you avoid getting deeply involved with someone before finding out they want kids if telling them upfront doesn't work?

edit: After some reflection, I'm probably over-exaggerating the friends not being supportive thing. They aren't really taking up her side, more just throwing up their hands and saying, 'what can you do', and my general emotional state is taking that further than it is intended. Mea culpa.