Nice in theory but fraught with problems.
My first thought is you don’t get to chose to be a father because you are, biologically, whether wanted or not. And, offering that choice in turn opens up new legal arguments for men to have a say in womens reproductive health. A very slippery slope.
If a woman chooses birth your suggestion provides the biological father with the convenience of avoid any financial input into the raising of his child while still being able to have a relationship with it….which could of course be dealt with with some sort of legal intervention, but that has the potential to be extremely distressing and ongoing given that peoples feelings change over time and a man may then find himself needing to cough up a massive debt before being able to have legal access to his child. I can think of lots of other scenarios that could lead to 18 years of messy and stressful family court battles.
It would make for an even stronger argument for abortion rights though, and given so many pro-birthers are men that would be an interesting turn of events.
It’s a bit of a wicked problem really, for which there is no perfect solution, and in my opinion the current one that holds a man responsible his child is the better of the two solutions because ultimately it’s what’s fair for the child and in most family courts I think that is always the first consideration.
One thing is for sure, men need to be just as vigilant in their birth control as women are expected to be.