No Choice here bit to man up and pay if it is his kid in spite of the mothers profession.
No choice?
Why should you assume the man must pay? Is it beyond the realm of possibilities to think that maybe HE can be awarded custody, raise the child himself, and the prostitute be ordered to pay him child support?
I'm inclined to agree. After all, the money is really for the innocent kid, not to "punish" the father or "reward" the mother. And anytime anyone, male or female, has unprotected sex, they have to face the possibility that a pregnancy might result, and be prepared to take responsibility for it.