Real World
It is at once simple and complicated:
• Person A argues that because of shared responsibility with Person B in causing a given Circumstance, only Person B has any obligation toward said outcome, which in turn bears particular requisite demands, i.e., is problematic.
Alright, you ready?
• He motions her aside and says, quietly, with tones of exasperation: "Hey, can we talk for a minute? Look, we both made this child. You need to leave support alone and take me off of the file."
When I ran across it not really so long ago, it was already twenty years old; perhaps not so strangely, I remember the time. There is even a Sciforums version of the issue that is, in itself, at once simple and complicated. Still, the amazing consistency by which the underlying issue fails to change is its own question; this particular iteration is especially bizarre.
Remember, though, we're looking at this as a presupposition. Whatever one wishes to do in order to dress up a justification or sympathy, that is its own thing; we are attending the argument as a presupposition, given
a priori; that was its underlying function over twenty years ago.
Additionally, do not overcommit; there remains a plot twist, which I've already mentioned, and it really is easy to fall into the ditch from there.
†
A secondary consideration, per
#17↑:
Does an invalid presupposition asserted by a stakeholder utterly invalidate a given larger proposition?