Suddenly all the nights out with friends you crammed in before the birth seem a waste and evenings watching TV ignoring each other seem like luxurious indulgence of the worst kind.
After you have a baby Time Together Alone is something to be dreamed of, one day in the future, and thought of with trembling hope and disbelief.
"Perhaps one day we'll walk the Pennine Way alone" one of you might suggest.
"Or walk the Three Peaks!" cries the other one. If only we'd thought of that before, rather than sat on our arses every weekend reading the papers.
My daughter was born eight weeks ago. When she was three weeks old her Auntie Carrie came to stay. "Off you go," she said, "go out for a meal." The words tumbled out of her mouth like an incantation.
After weeks of intensive parenting, in the house together with the baby or out visiting with the baby (the odd no-you-have-a-couple-of-hours-off notwithstanding), we ventured out together. Alone. Terrified. Me in lipstick, Bob in an ironed – ironed! – shirt.
Never usually short of something to say to each other, we'd vowed not to spend the evening talking about the baby. You can probably guess how that went. On the journey to the restaurant we kept turning round in panic and finding her not in the car seat, on the ride home, we anticipated everything that could have gone wrong.
"What if Carrie doesn't realise where the nappy bin is?", "Does she know the order we've stored the breastmilk in? What if she reads the date wrong?".
We failed miserably in the restaurant too.
I texted Carrie: "How much longer have we got?"
"As long as you like!" she replied breezily.
Our hearts privately sank, each of us secretly hoping there'd been a problem that we had to go back and fix. "We'd better go back," we both said at once, "it's not really fair on her."
Of course we returned to find a happy baby and a happy auntie and just four hours later we were laying in bed, listening to the baby work her way into a cry and wondering when we would EVER escape alone together again.
A proper long escape came in the form of my partner's birthday. "Leave the baby with me for the afternoon," said his mum benevolently, "Take my son somewhere nice." A whole afternoon! She'd even suggested it could go on well into the evening if we wanted. Bliss! Excitement!
So, approximately a week before the birthday the arguments began. "Why don't we go to the cinema?" he said, a particular passion of both of ours.
"Isn't that a waste?" I said, "we can do that on our own any time. Let's go for a meal."
"But I don't want to sit and eat other people's food. I like my own cooking," came the reply.
"Well let's go for a walk," I said, "Come on you know you don't REALLY enjoy walking."
Backwards and forwards we went, trying to think of The Best Possible Use of the afternoon that didn't involve leaving the county or staying at home.
The argument continued all the way to grandma's, whereupon we dropped the baby off and went....to Ikea.
"How long have we got?" I texted Grandma, "As long as you like!" she said.
We walked back to the car, drumming our fingers on our jeans, absent-mindedly reaching for the babysling: "We'd better go back," Bob, or maybe I, said, "It's not really fair on her..."
Does this sound like you?