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in my analogy does the top? no right? he can GTFO or face the consequences.

Again, the baby has no such choice.

yeah, that's right, it doesn't, which is probably good since a fetus has no agency.

I don't know what you mean by agency in this context.

the ability to make choices for oneself

Neither does an infant. I don't think that means they should be killed at will though.

an infant is not stuck inside of anyone against their will.