While men don't have menopause like women, there's still the taboo of having a child at age 40 or older, and children from older parents can have health risks. These men are often part of a May–December Romance. A man can have a child at an old age for a variety of reasons:

His partner wants children. He knows he's too old for that, but he's a Henpecked Husband and gives in to her wishes. He sees parenting as a hobby and decides to have another child when