If a set of identical twin women married a set of identical twin men and each couple had children, those children would (genetically speaking) be siblings?

Think about it; identical twins are genetically the same, so if the sisters, let’s call them Sally and Suzie, married twin men, we’ll call them Tommy and Timmy, then each couple would have the same available genetic material to contribute to offspring. Sally and Tommy’s kids would have a similar genetic structure to Suzie and Timmy’s children. There is even a very very slight and extremely unlikely chance that one of  Sally and Tommy’s kids cold be identical to one of Suzie and Timmy’s. (The probability is vanishingly small, but it is remotely possible.) Then imagine if those nearly-impossible children married a set of identical twins themselves.

It makes you think.