OK, my post has completely changed after your more recent posts. OP, please consider REALLY hard, raising your child with a father who at best, seems to resent him.
Please do not think that your child will not notice. He will.
Please do not think that the relationship & love you have for your child will "fill in the blanks" because it won't!
Please do not think that this will not hurt your child, because it will.
Below (in bold) was what I had written before I changed it
Think about someone else...I am not talking about your partner, but your potential child. EVERY child has a right to be wanted by both parents. Every child has a right to live a life free of resentment by a parent who didn't want it
I wasn't wanted (by my mother) and spent 18yrs being told that is various ways, including her withholding affection, treating me differently to my siblings, manipulation, abuse, being clearly resented.
It isn't nice. It still hurts, over 20yrs on from going NC!
You can, and DO resent & regret children. For the sake of that potential life, no one should be forced to have a child they do not want.
I suppose he does take responsibility in the sense that he pulls out in time. I guess there's a chance of a mistake (on his part) but we haven't had one yet! If he is really adamant, he needs to start using proper barrier contraception. You can get pregnant with withdrawal, not matter how perfectly timed you are at pulling out.