Should he marry a second wife?

My very good friend approached me this afternoon. He has been married for 20 years. He got married in August 1994. He was 26 then. She was 19. They have no kids.


He met a friend, another woman. He told her his predicament and they both agreed to "try".
After their trial, she gave birth to a daughter for him.

All the families of the three people in question know all that has transpired. No one has blamed the man for what happened. In fact, the wife's father told the man that he has tried for waiting 20 years.
It is only the wife herself and her mother that are not happy about it all.

Now my questions.
1. Should he marry the mother of his daughter as a second wife?
2. Should he divorce his wife to marry the new wife?
3. Should he have more kids with the new woman? (he wants more kids)
4. Is the man right to do what he did?

Please tell me. He awaits my advice.