One of many such talks I've had :P I recently tried to break down the issue of abortion and a way to illustrate it as simply as possible, as well as why it's unfair for men to have a say in that decision despite that they then have to pay child support. Here's what I came up with.
Abortion = the woman's right to sovereignty over her own body. Legally, the woman has to be able to control what happens to her own bodily self. There's absolutely no way to make that "equal" between men and women. Because a pregnancy does not, and can not impose itself on the sovereignty of the male body.
Child support = support for a living, breathing child. Legally, that child needs to be cared for. And should the man want to take care of that child physically, women have to pay child support as well, so insofar as child support goes the laws are equal. So, what's best for this child is the bottom line here.
To put it in even more simple terms:
I'll break down the situation into mathematics for each step of this process.
Woman: Has sex +1, Carries Pregnancy +1, Cares for child after it's born +1
Man: Has sex +1, Cares for child after it's born +1
Guys who argue men should have a say in that middle step, or should be able to opt out of child support, seem to be arguing it by this logic:
Woman: Has sex +1, Carries pregnancy +1
Man: Has sex +1, Pays for child after it's born +1
And want to make the situation look like this:
Woman: Has sex +1, Carries pregnancy +1, Cares for child +1
Man: Has sex +1
The numbers speak for themselves why that kind of set up is unfair. They both have sex, they both have to care for the child after it's born. Their responsibilities in both these situations are equal, because they each play a part. But there's nothing in the guy's experience of this process that equals that middle step, so why should they have any say at all?