WIBTAH if I do not support a child, my teenage son does not want and is not prepared to care for?

My son and his girlfriend are 16 and they were dumb, I had the conversation, provided the condoms but alas shit happens. His girlfriend is pregnant and she would like to keep the child, my son is by no freaking means ready to be a parent, I love him, but I would not trust him to care for a goldfish let alone a baby. She does not want put it up for adoption, she wants to raise the child. She cited some teen parents that made it work and claims they can make it work.

Thing she is not getting is, it could work if both parties want to be involved, my son wants no part of this, and she cannot force him to be involved she will be a single mother end of story. I am also not willing to go back to raising a baby, and her parents are not either. They even told her if she does keep the kid, they will support her as they are legally responsible to, but they will not support the baby. My guess at 18 they will also kick her out.

I am on the fence cause I also do not want to go back to taking care of a baby, I did it as a single father not really looking forward to sleepless nights and all that shit all over again. I was two years away from him going off to college for fucks sake, rip me.

Reality is this, if they have this kid they will need a shit ton of support, and to be honest that is support I really do not want to provide. His girlfriends parents pretty much already told her at 18 she is gone, minimum wage is not enough to raise a family, not like they would be able to finish school without support,

No matter how I look at this, if she keeps this kid she will need my support. I know it I am making it seem like she is being selfish and I guess to a degree I am, because she does not understand her keeping this kid impacts not just herself but everyone else around her.

I am a fucking loss, so let me have it reddit WTF do you recommend I do here?

Edit Yes it is a throwaway account, do not want this on my main.