Tension. Unbelievable, unbearable tension. Followed by horror. That’s potty training.

The first day without nappies goes badly. Eight changes of clothes. All wee. He does not poo at all. I want to give up.

Day two. The tension at play group is hell. I literally don’t know what I’m going to do if he does a poo here, other than call 999, which is probably frowned upon. But amazingly, no wee, and still no poo. Swimming, he wees on the pool side. Don’t think anyone notices. At soft play he wees in an inaccessible soft corner and a lovely mum helps me mop it up. I end the day mentally and physically exhausted. Still no poo. At all.

Day three. The poo tension is now unbearable. My son hates the potty. His little sister can’t get enough of it, she sits on it, stands in it, fills it with toys, puts it on her head. I take it off her and bribe my son back on it with his favourite TV program and innumerable special rewards. He’s there for an hour. No wee. And no poo. It’s been three days since he last pooed. His bottom is like an unexploded bomb.

Back on the potty. No one leaves this room until something comes out of my son’s bottom. If he can just do a poo, I can breath again.

Finally, after another hour of pep talks and promises and groaning and negotiating, it comes. It’s not huge, but it’s there. A real nugget of poo. I can’t believe it. I babble incoherently, pointing at it, my voice getting higher and higher.

“You did it!” I finally managed to say. I grab my son, pooey bum and all, and hug the life out of him. “Well done, son! I love you.” The emotion of the last few days come gushing out. I tear up. “God that smells awful, son.” I laugh with joy.

I have to share this moment. I take a picture of it and send it to my wife. Maybe I should keep the poo for her. She’ll love that. Probably.

I hug my son again. He’s happy for me, but a little bemused. The stench is eye-stinging, but nothing can spoil this moment of pure parental joy. Proudly I look in the potty again.

The poo is gone. For a moment my brain stalls.

“Everyone freeze.” I screech finally.

My one year old daughter looks up at me innocently. I check her hands. “Where have you put it?” I hiss.

She grins.