I don't know. I love my main set of Twins Dylan and Zephyr, but I have to admit they are a handful. When I started, I had this pair of twins...
Meet Dylan and Zephyr
https://live.staticflickr.com/65535/51617996401_c98fd1f5a7_k.jpg Then I had a single... And that was fine. I was trying to get Triplets when I got my first set of twins. You know, achievements...
Meet Ember
https://live.staticflickr.com/65535/51462674348_b8605b350d_b.jpg Then, without trying, I got this set of twins...
Meet Jade and Juniper
https://live.staticflickr.com/65535/51618278001_7044524a21_k.jpg I made it a full house by adding a cat.
https://live.staticflickr.com/65535/51618513158_590ac84160_b.jpg I started a legacy, and the legacy ended up with the same trend. Only every heir had a twin.
Spoiler (Highlight to read) Kylen and Rylan
https://live.staticflickr.com/65535/51618278546_dd905b9486_k.jpg Kylen had twins... Because I was playing a legacy and Kylen turned out to be Gay, I rolled with it and allowed him to have a baby. I don't normally do that, but...
Meet Lir and Loch
https://live.staticflickr.com/65535/51619148120_6ebd803902_k.jpg Eco Living broke my save, so I ended up only keeping Lir when I started over with Lir as the Founder.
https://live.staticflickr.com/65535/51617447627_a7b6759d54_b.jpg Kylen and Rylanhttps://live.staticflickr.com/65535/51618278546_dd905b9486_k.jpgKylen had twins... Because I was playing a legacy and Kylen turned out to be Gay, I rolled with it and allowed him to have a baby. I don't normally do that, but...Meet Lir and Lochhttps://live.staticflickr.com/65535/51619148120_6ebd803902_k.jpgEco Living broke my save, so I ended up only keeping Lir when I started over with Lir as the Founder.https://live.staticflickr.com/65535/51617447627_a7b6759d54_b.jpg
These are my cursed (or Blessed) couples.
When I played my first Alien Household, I also had twin Alien Boys... I didn't get screenshots then.