1. What you are alleging you have to take its stock value very seriously by proof beyond reasonable doubt otherwise it will boom back seriously on you.
2. In any case till the marriage is alive one has to remember that relationship between the parents may not be sanctioned by law but the birth of a child in such relationship has to be viewed independently of the relationship of the parents. A child born in such relationship is innocent and is entitled to all the rights which are given to other children born in valid marriage such as maintenance, education, food, and medical and if girl child then marriage expenses too etc. etc.
3. At this stage I suggest find out the DNA imprint by means of off the record (means from private lab tests it costs somewhere around 18 K each) and then come back here for next step under civil and criminal Laws instead of first worrying about the money part which anyhow you have to give either today or tomorrow till your wife in future post civil divorce from you remains un-married. But all these are too time consuming and it is first suggested ot get proof before launching case.
{Also there is no need to reply to time pass enquires some time pass person ask here like above time pass person which are all irrelevant at this stage;
When did it happen
Where you in office or at home or in park
Was it cold night or warm night
What he wearing
What she wearing
Was it moon night or black night or candle night etc.
Were you under the table or under the bed so on so forth these idiots ask here to sprinkle chilies to your hurt cause title post}.