My travel companion keeps shopping after boarding starts, and I am done chasing him

My friend shops in airports as if the gate is a rumor.

At our first connection, he disappeared into a bookstore after the boarding time appeared on the screen. I called him twice. He arrived carrying a magazine and acted surprised that I was tense.

Today he has done it again.

We are at the gate for our return flight. Boarding has begun under the airline’s current process, which we need to follow directly. He said he was going to buy water. Ten minutes later, he texted a photograph of a sweatshirt and asked which color I preferred.

I wrote, “They are boarding. Come back now.”

He replied with a thumbs-up.

I am holding his small backpack because he left it beside me. That detail has quietly made me responsible. I cannot simply board without deciding what happens to his bag. I also cannot make him move faster by sending increasingly urgent messages from twenty stores away.

This pattern is not forgetfulness. He believes airports manufacture fake urgency. In his experience, lines move slowly and there is always time. In mine, the cost of being wrong is large enough that I do not want to run the experiment.

We have argued about it outside airports. He says my clock-watching makes travel stressful. I say his refusal to return makes me the unpaid alarm system. Both statements may be true, but only one of us keeps leaving the gate.

I need a rule for now and for future trips. I could send one final message saying I will board according to the airline’s instructions and he is responsible for himself. I could leave his backpack with the appropriate staff only if they direct me to do so, but I should not improvise with unattended belongings or security procedures. I could wait until the latest permitted moment, which would repeat the exact arrangement I resent.

What is fair? One clear warning and then board? Refuse to hold anything he needs? Stop traveling together unless he agrees that gate time is a shared commitment? I do not want to punish him. I want the consequence of wandering away to stop landing in my lap.