The bus I take is essentially a coach, always plenty of seats even at busy hours.
This morning I approached the bus stop, a woman was already there, and I saw her glaring at me because I was standing in the bus stop rather than at the side.
She then let another woman on first who'd perhaps been there longer than she had, then got herself in front of me and looked at me making sure I wouldn't get on before she did.
It's all a bit petty really, the bus was almost empty, it's not going to go without you.
If there were a pregnant/vulnerable/elderly passenger getting on and I could see there weren't many seats left then I'd let them on first.