The ultrasound is going to take longer than expected. Every measurement required (femur, head circumference, abdominal circumference, heart rate, etc.) must be done for each twin. The tech steps out to summon an MD, who will make certain she is labeling the twins correctly when she records the measurements.

Darlin and I are a alone for a moment. I'm shaking my head and staring at the screen. "Jesus. Twins. Holy cow."

Darlin is laughing. Her belly with the jelly shakes. She wipes away a few stray tears that, as she lay prone, are making tracks for her ears.

"You are amazing," I say to her, and she laughs more and wipes away another tear.

The doctor is saying, "This one is A. This one is B."

"Just don't call anyone C," I interject. Jesus. But the truth is, we're thrilled. We love being parents, tiring and frustrating as it sometimes is. It is also the single greatest thing that has ever happened to me.

I call my office and tell them I'm going to take half a sick day. See you around lunchtime, I say.

We had almost stopped after two, at least I think that's what happened. Darlin didn't seem to be in favor of having a third, and I deferred to her primacy in the matter; she was the one who had to gestate the little monkey, push it out of her womb, and then nurse it for several months, all while keeping her business afloat. Then, as I moved extra clothes, books, and other items to the porch one day so that they could be picked up by the Vietnam veterans association, I asked if I should give the baby stuff away, too.

To my surprise, she said, "No."

Two kids never seemed like enough to me, for purely selfish reasons. In the long run, it seems to me that family is mostly responsible for the joy in one's life, at least the joy I find important. I know that your relatives can be responsible for most of your misery, too, and that some find little joy in their family. But that's not my experience. To get old and find myself alone sounds to me like a terrible fate. I know a couple who had two kids, leading to one grandchild, who they literally lost contact with against their will due to a contentious divorce and bitter custody battle.

I've long joked that my family tends to produce kids in multiples of three. I have eight brothers and sisters. (I have no idea what my parents were thinking, having nine kids. "You were all mistakes," my mother once told me cheerfully.) Two of my sisters have three kids. My brother screwed up the pattern by stopping after two boys. On Easter Sunday, 2008, we went to my sister's house for dinner. We hadn't told anyone that Darlin was pregnant again. I asked my eldest brother to sit for a photograph with two of our nieces.

"What do these three have in common?" I asked the crowd (my family always makes a crowd) thronging my sister's living room and kitchen. Another brother--the mathematical one--said, "They are each the third child in their families."

"Exactly! And why is that relevant to anything?"

There were a lot of puzzled looks, and then I watched the realization dawn in my eldest brother's face. "You're having another baby?"

Big excitement at an already festive event. The kids--all 10 of my mom's grandchildren were there--loved the news. Lots of squealing.

Weeks later, knowing that we are having twins, I find myself telling people, "I thought we were brave going for number three. I thought that was a big family. I'm not feeling so brave anymore."

I tell others, "If I had a pocket knife, I would have vasectomized myself in the parking lot of the hospital."

Now, people ask me how I'm doing, and I say "Never better," and I mean it. Or I say, "Very well, in the Darwinian sense."