Danny boy.

You are three today.

Happy birthday, little love.

We had a birthday party for you four weeks ago, because your mum is super-organised and because I am not.

I arrived, breathless from walking too fast and too far straight from work and your mum shot a worried scowl at me. I sidled around her (after a quick, hard hug and whispered friendship) with a sheepish grin and your brother giggled and gave me one which was even quicker, with all the briskness of a six-year-old who is far too cool.

Of course, that didn't stop him from falling asleep on me later. But we won't tease him much about that.

And by that time you'd realised someone was here, and you were holding up your arms, opening and closing your fingers so I'd take them in mine and let you draw me close. You started as you always do, with all the finesse of a toddler-turned-little-boy, stroking over my hands and up my arms and then finding my face.

It's the nose that makes you sure of me. It always has been. As soon as you find it that startling, breathtaking smile tears across your face and you fling yourself forward, knowing that I'll catch you, because I always do. A happy yell escapes you. You don't know that, because you can't hear it. But you can see my smile. When I let you go, your hands reach for my face again and trace my grin.

You make the sign for my name - my sign, the one you chose and started using and which doesn't have any real meaning except to say you. I know you.

And then you beckon with the grabbing motion which says gimme, a cheeky twinkle in the eyes that can't see. Please is still tricky.

What Danny think? I sign.

Dragon, you mime, making your hands into claws and wriggling your bum enthusiastically with a pretend tail. And your mum and I share a chuckle and I press it into your hands. You don't like wrapping paper. It's just one more thing to feel, and you'd rather spend the time lovingly squishing and pulling and grabbing your new toy.

You may be the most careful little boy I know, but c'mon, you're still three.

We have a "feelie" adventure trail, which involves coveralls and paint and furry things and shiny things and bumpy things. You love guessing. It's your favourite game. Anne is here, helping us teach you new words when you don't know what something is. And you're not the only one tasting each new sign as it comes. Your mum is watching just as carefully, mouthing the word silently and practising with each addition to your vocabulary - and hers. "Talking" is still a relatively new thing.

And when the day is over and your chocolatey mouth is wiped and your 'grown-up' bunkbed is waiting, you turn suddenly and sign something else.

It isn't new. We've signed it to you again and again, tracing it gently on your round little face and body. But you have never signed it back before.

Love you. 

You wait for my reaction. You're sitting there in a lion onesie, clutching that silly new toy with its googly eyes and you have no idea you've just rocked my world.

Love you, I sign back, crossing your chest and pressing my hand shakily on your heart. And you nod as if it's only natural for you to give me this most precious gift on your birthday and let me hold you close, until you wriggle sleepily to get down,

because you may be beautiful and complicated and as different from other boys your age as can be, but c'mon, you're three.