I can understand the sentiment, but it ultimately comes down to what can be legally provable. Now, it is easy to prove that you didn't have a committed relationship with somebody. It is harder to prove that you were in a committed relationship but didn't want kids and took preventative measures.

Unless both parties have signed a clause saying such, you're going to have a hard time proving you didn't want or expected children.

There isn't one answer that will assauge all offended parties in all circumstances. As it is, the US justice system regarding child support is fucked. I'd like it to change (even living in Australia atm), but there is only so much you can expect from a justice system.

It comes down to trust. There are plenty of stories of people who trusted their SO and got screwed. That absolutely sucks. People can change over time, and they can also deceive you.

I like to believe that if you are objective about it, and know what you are looking for, you can meet the counterpart of your dreams. I have met mine. I don't hold any illusions that someday that might crumble to ashes, and she might reveal her true face to be a smoldering Balrog. I hope that doesn't happen. I don't expect that to happen. If it does, I hold that as bad judgment on my part, and not hold it against her.

What I do know is that I make my relationship choices based on how I feel and try to assess that in an objective light. If I am doing all the work, and maintaining the glue in the relationship, I would look into that. I feel at the moment we have a good give and take. If that changes, I hope I can notice it.

As it is, there is no certainty. There is only trust. You just have to be careful about who you give it to.