Courtesy apparently is not so common anymore.
Yesterday I was showing property. I was inside a house with my client when another agent barged into the house with his clients, kids and friend in tow and proceeded to waltz through the house. He never acknowledged that we were even there. He did not leave his card as is standard business practice, so I don’t even know who he was. How incredibly rude, inconsiderate and unprofessional.
It is common courtesy to let the agent already showing the property finish and then proceed with your own showing.