twibling

— When people press me about their status (“But are they really twins?”), the answer gets long. The word “twins” usually refers to siblings who shared a womb. But to call them just “siblings” instead of “twins” also raises questions because full genetic siblings are ordinarily at least nine months apart. And our children could be considered the same age because they were conceived at the same time (in the lab) and the embryos were transferred at the same time. If the person continues to quibble about whether they really qualify as twins (as, surprisingly, people often do), instead of asking why it matters, I announce airily that they are “twiblings.”