My son has two girlfriends. He is 10.

Two of the girls in his fourth grade class asked him to be their Valentine. He is proud of this, but he doesn't want me to know he's proud. He wants me to know about the girlfriends, but he doesn't want that to be obvious either.

He was in the car with me Friday, sitting in his booster seat, when I asked him about his Valentine's Day. He stared straight ahead, silent, a smile tugging at the corners of his lips.

"Did you get any Valentines?" I asked.

He nodded, and looked out the window, away from me.

"From who?"

"Maggie." He paused. "And Kara."

He was looking forward again, holding back a grin.

"Did they both ask you to be their Valentines?"

He nodded. "And one of them said it straight up."

"Said what?" I asked.

"You know."

"What? That she loves you?"

The grin broke free. He put his head in his hands to stifle a laugh, looked back up and tried again to close his lips over his teeth -- to no avail. His face was flushed. My son was blushing.

He would not tell me what he said in response. But he owned up to the fact that he now has two girlfriends. Kara, he said, has been hanging around him more since Valentine's Day. Maggie hasn't been around as much, he said. I suggested that perhaps Maggie was a woman scorned who had retreated to lick her wounds. I asked - with a deeply buried grain of seriousness - how he planned to avoid hurting one of them.

He tried to look annoyed with me, but grinned again. "Mom! Stop!"

Of course, I did not stop entirely. Just momentarily. After all, I had an entire three-day weekend ahead during which to spread out the teasing.

I also needed time to figure out how I felt about it. I was, and am, a jumble. Part of me is proud - after all, he's the fruit of my loins and a cute little fruit at that. Part of me is happy that he's popular. That he won't suffer the pain of being an unattractive child and an almost too-late bloomer. Hopefully, if he gets an early handle on relationships, he'll make fewer mistakes in that area of life than I have.

Another part of me is alarmed, and a bit sad, as though he's turned some corner and is standing at the starting point of a road down which I cannot follow.

The logical part of me dismisses it as a fourth grade crush. Or two. They start these experiments of the heart earlier, I remind myself, than we did.

But later that night, when he fell asleep, I studied him with different eyes. Looking down on him, I saw the rounded forehead, long, dark eyelashes, freckled nose and flawless skin. Asleep, his face softens back into that of a toddler. His cheeks are soft, round, without definition.

His body is slight, and likely to remain so. The only hair he has is on his head. Shirtless, his shoulders jut out from his back like two featherless bird's wings. I can count almost every rib.

He uses a booster seat, though he's long since past the age at which the law deems it necessary. He can see better, he tells me, with the extra few inches it gives him. I don't argue.

He still sits on my lap. He likes to lay beside me, spoon style, to watch TV. He falls asleep with his blonde head in my lap. Sometimes, in public places, he still reaches for my hand.

He is, to me, only a larger version of the diaper-wearing boy who, after I put him to bed and returned downstairs, pulled himself up and out of his crib in a nightly quest to find me. I would find him on those nights asleep in the hallway where he had wearily surrendered.

But he's changing, as he should, evolving away from the dependent child to a young person with opinions, interests and yes, secrets. Fond as I am of the days of young childhood, he becomes more interesting with every year.

He has initiated conversations with me about evolution, slavery, solar power and the value of friendships.

He's gaining his own taste in music. Green Day, Tom Petty, Bowling for Soup, Eminem. He rejects, with increasing frequency, the clothes I choose for him.

He's funny, and loyal. Recently, he made an observations about one of his friends' occasional bouts with exaggeration. He overlooked it, he said, because "he needs me" as a friend. The statement both touched and concerned me, but they now seem to have passed safely through those rough waters, back to almost nonstop laughter and in-depth discussions about PSP games.

I believe his compassion extends to me, something I have not yet figured out how best to handle. He laughs at my jokes, but last week, shook his head after a particularly lousy one.

"Mom, sometimes I worry about you," he said.

"Why?" I asked. "Because my jokes are bad or do you just worry about me generally?"

He paused for a split second. "Both," he said.

Like any mom, I think my child is a wonder. I am awed by my good fortune.

But he's in some sense on loan to me, I know. Already more than halfway to legal adulthood. Already looking excitedly toward college, which he is convinced - based on my censored accounts - will be the best years of his life. I hope they are instead just the beginning, an extension of what he remembers was a happy childhood.

I hope these two girls are just the beginning of a long string of friends and admirers he'll find along his way.

Irrationally, I hope that he breaks no hearts. Even more so, that his heart is never broken.