My twins had never spent more than a night apart. When one went to Europe for 6 weeks, they barely spoke.

• My identical twin sons have done everything together for 19 years.
• They'd never spent more than a night apart until Thomas left for Europe.
• Six weeks of silence might be the healthiest thing that's happened.

My identical twin sons are 19 and have done everything together their whole lives. Same schools, same sports teams, same friends, same produce department at the grocery store. Until last month, they'd never spent more than a night or two apart.

Then Thomas got accepted for a two-week college placement in Italy, and his best friend Brad landed the same one. They decided to tack on another four weeks and travel Europe together. Charlie stayed home.

I helped Thomas plan his trip, giving him recommendations for cities to visit, tips on getting around, and more unsolicited advice than any 19-year-old wants from his dad. I probably talked about the trip more than he did.

Thomas sent Charlie 1 text in 6 weeks

I texted Thomas most days about his trip, and he replied to about a third of my questions, usually two or three days later. His updates were minimal. "Munich. Walked around, saw lots of stuff." "Prague. Cool. Walked around. Cheap beer." My wife said I should've known better than to expect detailed updates from a 19-year-old travelling Europe with his friend.

I expected the brothers would at least stay in touch, but Charlie heard from Thomas even less than I did. Only once.

Early one morning, our time, Thomas texted asking Charlie to log into his sports betting account and place some bets for him. Charlie was getting ready for work and said no. That was their entire communication for the trip.

Charlie didn't want to see a single photo

Thomas sent me photos from across Europe, and I'd be happy to show them to Charlie. Every time he'd say he wasn't interested, and if I tried to show him, he wouldn't look up from his phone.

With Thomas and Brad away, I half expected Charlie to feel the gap. His twin and their best mate were backpacking across Europe without him. But if Charlie felt anything, he didn't show it. He picked up their shifts at the grocery store, hit the beach, saw his girlfriend, and went out with mates.

You wouldn't have known anything was different. He never once asked about his brother's trip.

But then Charlie checked a score he'd normally never care about

People have called them "Charlieandthomas" their whole lives, one word, like they're a single person. So when they went six weeks barely exchanging a word, I found it strange.

But then, at dinner one night, I mentioned that Thomas had attended an Ajax match in Amsterdam the previous night. It finished 4-1. Charlie said he already knew. He'd checked the score as soon as he woke up that morning.

Charlie follows some soccer, but he wouldn't normally care about an Ajax game. The only reason he'd check the result was to see if his brother saw an interesting match. He was keeping tabs, in his own way.

I'd worried about the silence at first. But the Ajax score changed the way I saw their six weeks apart. When you've shared every day of your life with someone, you don't need to check in to prove you still care.

Thomas came home, and Charlie barely looked up

The night before Thomas landed, I asked Charlie if he was glad his brother was coming back. He shrugged and said not really. When I asked whether he thought Thomas might bring him a gift, "0%" was his response.

My wife and I were at the door when Thomas walked in, pulling him in for hugs and firing questions about the trip. Charlie was on the couch and didn't get up.

After a while, Thomas reached into his bag and started pulling out gifts. Something for me, a few things for my wife, and then a cap for Charlie from Wolfsburg, his favourite European soccer team. Charlie tried to play it cool, but I could see the excitement on his face.

Six weeks of silence, one rejected betting text, zero interest in any photos, and yet Thomas knew exactly what gift to buy.

They were back at work together in the produce department the next day.