On a warm June day in New Jersey, I filled the first box. I'd flown east to help my father pack, and the living room seemed like a good place to start. Hand-scrawled "Happy Birthday, Dad" cards gathered dust on his mantel next to the routine assemblage of geriatric humor from friends ("What's so great about getting older? You save a bundle on shampoo!"). One card, though, stood out: Its yellow cover sported the earnest face of a chimp and the words "You are my lover and my best friend . . . " Inside, the chimp was grinning and jumping up and down on a rumpled bed, shouting, ". . . and my naughty, naughty mattress monkey!"

Talk about too much information. Some things a child should never have to see, even at the age of 42.

The cards were from his seventy-seventh birthday, seven months earlier, the first he'd had to contend with after my mother died of cancer the year before. That the cards were still on the mantel did not bode well for the task at hand; my father was a notorious accumulator, and he was moving from a four-bedroom, three-story house in the suburbs to a one-bedroom apartment in Manhattan. But the salacious monkey did augur well for his future. My siblings and I had feared Dad would break down when Mom died. There'd been bleak episodes of clinical depression over the decades, months when he wandered the house in his oldest bathrobe and took long naps facedown on the living room rug. It didn't take a giant leap of imagination to picture him yielding to grief's pull. We'd made plans accordingly: a retirement condo near my brother's home, Dad dining nightly with my brother's family, eating his broccoli and reading to the grandkids. But look at him--now: the mattress monkey, bouncing into new life and a bachelor pad in the city.

This was better, of course. It's just that sex and your father are two topics that don't mix well. As kids, we figure out early on that our parents must have "done it" at least as many times as there are children in the family, but we prefer to think that the story ends there. My friend Mary once asked her prim 79-year-old mother why, since she'd always been such a staunch Catholic, she'd had only two children. "Well, dear," her mother answered, "your father always had difficulty maintaining an erection." According to Mary, it was a bit more intelligence than she'd needed and an image she could have done without.

I was there when my mother died, then stayed awhile, helping Dad transition from essential caretaker to aimless widower. A methodical man, he came up with projects to give us purpose, such as hauling derelict lawn equipment from the shed to the sidewalk-rusty mowers, toothless rakes.

I'd hated leaving him, but I had bought a ticket to Paris months earlier and had a friend with a flat awaiting me. My father's face was gaunt with pain, his sagging frame dwarfed by the home in which he and his now dead wife had raised their family. "Go," he told me as we hugged good-bye. His shoulder blades felt sharp through his summer polo shirt. "You've been a huge help, and I hate to see you leave, but I need to learn to be alone."

I bought a fancy quad-band cell phone, the kind you can use in France to call home. My friend was at work and the sun was warm on my back as I sat in the Bois de Vincennes and dialed New Jersey for the first time. Couples strolled, very French-like, along the lake path, and a cluster of old men sat on a bench arguing about the world, or their teeth, or the price of a croissant--my French isn't so good.

When I phoned my father, he said that he was sad but OK and mentioned walks in the neighborhood, movies with friends and meetings with the bereavement group we'd pushed him to join.

Then he asked how I'd feel if he started dating.

My parents had had a loving marriage, 45 years of it, and in the end, as Mom sickened, Dad could not have been more tender and caring. My mother told me that when she was in pain and he brought her a pill, the look on his face was the purest expression of love she'd ever seen.

I knew that my mother, always 10 steps ahead, had told him during her last months that if he wanted to see other women after she died, he had her blessing; she even offered him a list of sanctioned names. I'd asked him once who, exactly, was on it, but he'd just given me a sly smile and said, "None of your business."

In his tenor voice, sounding oddly close even though he spoke from the other side of the Atlantic, he told me that after much lonely traipsing from room to empty room, he'd decided that he didn't want to spend the rest of his life by himself. He'd enjoyed being married, and if he wanted to marry again, he needed to get busy.

"I just want you to be happy," I told him, or some such version of the right thing to say. Then I walked fretful laps around the lake, lost in the muggy French haze and my own irrational funk. I hated the idea of my father in pain. Still, I was disturbed. It had been just two weeks since my mother died. I kept trying to recall the part in Hamlet when the funeral meats serve as wedding fare. All I knew was that I approved, cognitively, of his starting a new life, but that my emotions were not yet there.

My father was a market researcher, and work had been his obsession. My mother took ill shortly after he retired, and caring for her became his new vocation. Now, once again, he had a project to design and implement. Eschewing the list of approved ladies my mother had willed him, he wrote ads and placed them in local newspapers. A latecomer to the computer age, he turned to me for help with online dating. When I returned from Paris and my feelings had caught up with my good intentions, I introduced him to JDate, Craigslist and Match.com.

Some weeks passed, and I asked him how it was going. "Oh, Stephie," he said, "this dating is such hard work! I'm exhausted!"

Apparently, a healthy, sweet man in his late seventies was quite the valuable commodity among women in his age group. He was swamped with responses.

"I have phone messages to listen to, e-mails to read. Then I have to take notes on them all, call them, talk with them and meet them for dinner. It's a good thing I'm retired."

He'd drive home after his encounters and stay up late annotating his lists. I could picture him hunched over his yellow lined legal pads, making thoughtful comments, ranking his various options. Craigslist, though, was a disappointment. "The descriptions people give are too pithy," he said. It turned out he hadn't understood that the subject lines-"looking for a boyfriend" and "coffee? I'm 65"-were actually hyperlinks that, once clicked, revealed fuller profiles.

More weeks of slogging through the mature women of northern New Jersey and at last he found the one: We'll call her Faye, she of the bouncy monkey card. She was vibrant and active and full of fun, close to him in age (though she'd lied in her own JDate blurb, claiming to be 74 instead of 76). They fell in love.

Now Dad was beaming instead of clinically depressed. He was planning a trip to Mexico, moving to New York and buying Viagra from Canada by the cartload. So long as I didn't have to watch him in mattress mode, I was delighted that he was so full of life. So she liked to call him Jackson instead of Jack, the name he'd gone by for 77 years. So she asked him to let his thin, receding, straggly gray hair grow into a ponytail-a request that he refused to yield to, despite the happy light in his hazel eyes. She was warm and intelligent and had a sparkle about her. I made peace with my ambivalence. After tending to my mother as she died, I was more than happy to be free of the father burden I'd thought would be my immediate filial duty.

They came to visit me in San Francisco. They cooed and joked. They held hands; my father smiled more than I'd seen him do in years, and the tic in his left shoulder he'd acquired during my mother's last months had disappeared. I was spared the more intimate details.

I told the story to all my friends ("So I met Faye, and she's calling him Jackson") and found I was in good company. Plenty of people had aging parents seeking new romance. "It started at my father's funeral," Wendy told me. "They were buzzing around my mother at the cemetery! One old guy even came up to me at my father's grave and handed me a card and said, "Have her call me…."

Her mother remarried one year later, at 75. Wendy recalled that when her mom and the new boyfriend came to visit, shortly after becoming an item but well before marrying, she had told them, "You'll have to sleep in separate rooms, like you made me do when I was 20." They thought that was very funny and proceeded to cohabit in the guest room.

But, like me, Wendy was relieved that her mother had found new love, both for generous and for selfish reasons. "I like how he treats her," Wendy said, "and I'm thrilled I don't have to take care of her."

I Googled "geriatric sex" one day, and the National Council on Aging's Web site informed me that 48 percent of seniors are sexually active once a month and nearly 75 percent of those randy oldsters find their sex lives as emotionally satisfying as they did in their forties-or more so. I read the stats to my husband. He just raised an eyebrow and said, "Let's keep a good thought."

I could easily embrace the prospect of happy frolics in my own long-term future. Only when contemplating my father and his souped-up sex life did the figures make me squirm. I chose instead to focus on health. Take the well-known statistic that married men live longer; clearly a man with a sweetie was better off than one without. Men are often accused of ignoring their health, but here was my dad, robust to a fault.

The honeymoon was short-lived. Half a year after taking up residence in Manhattan, just days before departing with his sweetheart for a month in Mexico, he suffered shortness of breath. Instead of a sun-drenched vacation, he got a quadruple bypass. The operation went exceedingly well, but the aftermath didn't. Somehow, while his system was vulnerable--maybe from all the prophylactic antibiotics, no one knows for sure--he contracted salmonella. It took up residence in his blood and went undetected for months.

When he complained of pain, the doctors called him a whiner. By the time the diagnosis was made, the infection was in his bones and untreatable. When the pain intensified, the doctors said that the agitation caused by his medications made him an unreliable informant. That's when Faye dumped him. She just couldn't face the same emotional agony she'd been through when her husband died, so her visits became scarcer and scarcer, then stopped. Finally, my father's long-delayed depression arrived and settled in for the duration.

A few months later, he succumbed to the ailments he no longer had the will to stave off, the pneumonia and bladder infections elderly people are prone to when antibiotics stop doing their thing and the heart throws in the towel.

After he died, we had to clean out the Manhattan bachelor pad. My sister got the kitchen, my brother took the bedroom ("What do we do with Faye's nightgown?" he called from inside a closet), and I tackled the bathroom. The cabinet above the sink was a pharmaceutical bonanza, a jumble of cholesterol pills and stool softeners, insulin syringes and pain patches. Among these medicinal odes to old age, I found my dad's Viagra stash, and I smiled. It was inspirational, a jubilant, life-affirming gift. There were boxes and boxes of the stuff-a vigorous display, the mattress monkey's last Cheshire grin.