(Some men don't believe they are a true cuckold until their wife has a child to another man. Caring for another man's child to them is proof their wife's happiness cums before theirs. Raising another man's child can be a Badge of Courage and Commitment (in a cuckold's eyes))
I agree on this and there is one more reason for us cuckolds wanting their wives getting pregnent with another man's semen - Her lover being the alfa male and even a successful intelligent man, he wants the child to inherit the superior genes, instead of his, a beta male.
In my case, My wife's present lover is a young Muslim Boy, well endowed and with natural God given talent in satisfying women. He is clean and sophisticated, unlike what some people think generally of Muslims. He has great stamina, very intelligent. Even though He is nearly half wife's age, she has fallen for His charms. He is the son of a rich immigrant from India, settled in America. She is so impressed with his intelligence and his physical build, she wants him to be the father of our first child, hoping the child will inherit His genes. I fully agree with her. I think It is better than she having my child, I being not very successful in career and also not as well built as him.