His wife admitted to him that his children were from another man; what should he do?

No File Exists
Check below answers in case you are looking for other related questions:
Her husband cannot produce children and he is addicted to haraam things
Is it permissible for a man who is suffering from some sexual difficulties to get married?

No File Exists
Related Answers:
Ruling on what comes before consummating the marriage with one’s wife; is it haraam to have intercourse after doing the marriage contract?
She received a marriage proposal from someone who is infertile and her family rejected him
The widespread belief that it is makrooh to get married in Allah’s month Muharram
Her husband cannot produce children and he is addicted to haraam things
Is it permissible for a man who is suffering from some sexual difficulties to get married?

Recommended answers for you:
Fasting is not accepted if one doesn’t pray
Keeping a dog, touching it and kissing it
Commentary on the hadeeth, “A woman may be married for four things…”
Rulings on miscarried foetus
How can a woman determine that her period has ended so that she can pray?