Riddle Me This

I have a pair of brothers who happen to be fraternal twins*--which means they were born within minutes of each other, but don't look any more alike than the rest of us siblings. Growing up, they weren't particularly "twinnish". They shared a mutual interest in comic books and martial arts, but then, so do a lot of boys. So do I, for that matter! They did sort of have their own "twin-speak"... but really, they were just speaking in low tones, and the other three of us understood them just fine.

Anyway, eventually they grew up, as people do. One of them became a pilot and later a physical therapist; the other one, a physical fitness instructor and later an actor. Which is sort of parallel, but still not all that "twinly", right? Yet for some reason, in the same year, they married two unrelated women who happened to be born on the same day, within minutes of each other. One of these women used to joke that the two of them were "astral twins" who married real twins. We all thought this was very funny because the two women were then very different from one another.

Flash forward to the present day, thirteen years later, by which time both sisters-in-law have been undergoing recurrent psychiatric issues, for which they have been treated with everything from medication to therapy. Within the span of one month, one of them has asked for an annulment; the other, a divorce.

It boggles the mind that two people can be so unhappy being married to two of the nicest guys in the universe. (Well, you know, once the guys got done with tormenting their baby sister.) But leaving my personal opinions aside and just looking at it from an objective standpoint... It still boggles the mind, doesn't it?

Naturally, I need to explain the difference between identical and fraternal twins, because, you know, I'm just nerdy that way. Identical twins are born from the union of a single egg and a single sperm. Sometime during the pregnancy, the fertilized egg then splits, creating two embryos with exactly the same DNA--hence the term "identical", duh! Fraternal twins are the result of two different eggs fertilized by two different sperm during the same period of conception, creating two babies that are born at the same time, but which have different genetic mixes. So they're no more identical than any other siblings--except that they were, as my brother likes to put it, "womb-mates". This means that, theoretically speaking, fraternal twins can actually have two different fathers--which has happened more often than you'd think in the history of the world.