If you’re in line at the grocery store with a full cart and someone behind you has 1 or 2 items, do you let them go in front of you?
If I’m in the express lane or self-checkout no. That means I have a few items as well. Regular lane I do. Now one time I let someone holding a couple of things go and then she signaled to someone with a cart full of things to come over. The cashier didn’t let her go, made her go back to her place in line.