How exactly does this work? I'm fair to middling on building but fail miserably at playing the game. I DO know the mechanics of whoo hoo, just not really sure how putting extra males in a house would benefit an ID.
I'll explain it through.
For example, you start an immortal dynasty in Riverview. Your founder is looking around for sims to help them out, when they come across, say, Jon Lessen. Jon is an older adult, rich, attractive, but you don't have him eyed for your founder's spouse. Still, you'd like his genes in the family, so you move him in anyways.
Jon doesn't have to be useless. He might paint for you or do other dynasty things while your founder is out doing their things and marrying someone else. But at some point, Jon gets himself a girlfriend from outside the household. Maybe he finds something appealing in Roxie Lin. He goes to her house, Tries for a Baby, and three days later, Jon had a child that isn't a part of the household. And, in fact, Jon can have a lot of kids this way! He might end up with four or five kids with Roxie Lin, who never have to be a part of the household. Jon can also keep producing children as an elder and basically until Grim comes for him, because elder males can reproduce indefinitely.
And when your second generation heir is an adult, they can marry one of those Lin kids.
If you're as crazy as I am, you repeat the process once you notice that a desired male townie has gone grey. Move him in, find him a younger female mate, make children, and cheer when he goes to the grave.
In short, it's a way to keep a diverse gene pool. It's not needed to keep a dynasty running, but it ensures more interesting-looking immortals as time goes on and your immortals marry the kids or grandkids of those original townie men, and it does it without compromising household space
that much.
