“What are you so scared of?”

“Oh, you know, all the obvious reasons: I’ll never be able to sleep with anyone else ever again, I don’t want to be part of a smug couple who finish each other’s sentences, etc., etc.”

But my real fear was that it mightn’t work out, that he might run off with someone else—or more likely, go back to Janie—and I’d be absolutely destroyed. When you love someone as much as I suspected I loved Aidan, there was so much further to fall.

“I’m afraid that it might all go horribly wrong,” I admitted. “That we’d end up hating each other and losing our trust in love and hope and all the good things. I couldn’t bear it. Then I’d become an over-made-up lush with big hair who drinks martinis for breakfast and tries to sleep with the pool boy.”

“Anna, it won’t go wrong, I promise. This is good stuff, you and me, as good as it gets. You know that.”

Sometimes I did. Which meant that—like the urge I got on the top of a tall building, to just jump off—my biggest fear of all was that I might say yes.

“Okay, if you won’t marry me will you come on vacation with me?”

“I don’t know,” I said. “I’ll have to ask Jacqui.”

“Kill or cure” was Jacqui’s conclusion. “It could be a total disaster, trapped in a foreign country with nothing to say to each other. I’d say, go for it.”

I said I’d go so long as he didn’t once ask me to marry him. “Done,” he said.

I went to Ireland for Christmas, and when I got back, Aidan and I went to Mexico for six days.

After the cold and drear of a New York winter, the white sands and blue skies were so dazzling, it almost hurt to look at them. But the best bit of all was having Aidan on tap twenty-four hours a day. It was sex, sex, and more sex. First thing in the morning, last thing at night, at all points in between…

To make sure we got out of bed once in a while, we checked out the dusty local town and decided to do a beginners’ scuba-diving course, which was run by two expat Californian stoners. It was dirt cheap, and with the benefit of hindsight, maybe we should have been concerned. Also by the waiver form we had to sign, stating that in the event of death, mutilation, shark attacks, post-traumatic stress disorder, stubbed toes, broken nails, lost prosthetics, and whatever else, they were in no way, shape, or form responsible.

But we didn’t give a damn, we were having a great time, crouched in the tiny practice pool with nine other beginners, making Os with our thumb and index fingers and sniggering and nudging, like we were back at school.

On day three, we were taken out for our first dive in the sea, and although we were only twelve feet beneath the waves, we were transported to another world. A world of peace, where all you can hear is the sound of your own breathing and everything moves with slow grace. Swimming through blue water, it was like being suspended in blue light. The water was as clear as glass and sun rays filtered all the way to the bottom, to highlight the white sand on the ocean floor.

Aidan and I were mesmerized. Holding hands, we slowly flapped past delicate coral and fish in every imaginable colorway: yellow with black spots, orange with white stripes, and funny, transparent ones with no color at all. Shoals of them in formation, moving silently past us, heading for somewhere else.

Aidan pointed and I followed his finger. Sharks. Three of them, hanging around at the edge of the reef, looking mean and moody, like they were wearing leather jackets. Reef sharks aren’t dangerous. Usually. All the same, my heart beat a little faster.

Then, just for a laugh, we took out our mouthpieces and used each other’s spare “octupus” air tube, becoming one unit, the way “lovairs” in films set in the 1930s link arms and drink champagne from each other’s glass (and they’re always those shallow champagne glasses with the ridiculously wide rims, so that the champagne spills everywhere and you’re barely able to drink any yourself, never mind your loved one, but what harm).

“Wow, that was amazing,” Aidan raved afterward. “It was exactly like Finding Nemo. And you know what else it means, Anna? It means you and I have something in common. We have A Shared Interest.”

I thought this was his cue to ask me to marry him again but I gave him a look and he said, “What?” and I said, “Nothing.”

The last day was the big banana, the grand finale. They were taking all of us to deeper waters, which involved decompressing on our ascent. That meant hanging around for two minutes every fifteen feet while our air yoke resomethinged. We’d been practicing in shallower waters, but this time it would be for real.

But on the boat taking us out, events turned pear-shaped: Aidan had developed a cold, and although he was pretending he was in the full of his health, the instructor noticed and nixed Aidan’s dive.

“You won’t be able to equalize the pressure in your ears. Sorry, man, you can’t go.”

Aidan was so disappointed that I decided I wouldn’t go either. “I’d rather go back to the cabana and have sex with you. We haven’t done it in over an hour.”

“How about you go for your dive and then come back to the cabana and have sex with me? You can have both. Go on, Anna, you’ve been so excited about this dive and you can tell me all about it when you get back.”

Because Aidan wasn’t coming, I had to get another “buddy”—even though I hate the word buddy. Except when it’s used as an insult. (Example: “What’s it to you, buddy?”)

I got buddied with a man who’d been reading Codependent No More on the beach. He’d come on holiday on his own and had been buddied with the instructor for every other dive.

Final instructions were called to us before we jumped off the side of the boat, then we splashed down into that silent other world. Mr. Codependent wouldn’t hold my hand, but that was fine because I didn’t want to hold his either. Swimming along, we’d been near the ocean floor for several minutes—it’s hard to keep track of time down there—when I realized that on my last two inhales, no air had come out of my tube. I took another suck just to make sure, and no, nothing was happening. It was like the surprise I get when a can of hair spray is used up; it’s something that I think is never going to happen. I press and press on the nozzle thinking, It can’t be empty, then realize it is and that I’d better stop unless I want the fecker to explode.