A question that boggles the mind?

how is it possible that a very handsome 40 year old guy whom has a very healthy ual appetite, not have any children? I'm sure he doesn't always wear condoms especially not with his girlfriends, I'm sure all the females he sleeps with(and I do mean alot) arent all on the pill, and had to have at least slipped up once or twice right? how is this possible?