A megabus pulled up to the stop in Philadelphia. It just rained so there was a puddle very close to the step down from the bus, so as a young woman exited, the male Megabus worker helped her over the puddle and onto the street. The next person to exit was male and was not helped over, in fact, the Megabus worker just turned away.
So this is a classic example of benevolent sexism. Since I'm writing this on a bus on my phone, I'll link it later, but there's a great article on the Huffington Post I read recently about a study on benevolent sexism and how men and women perceive it. Basically, men don't notice, and when women are asked about it, it does annoy them. Benevolent sexism ranges from helping a woman over a puddle (but never thinking to do so for a man) to calling grown women "girls" and "ladies." I certainly don't mind when someone holds the door open for me, obviously it's just a lot more convenient when doors aren't slammed in your face while you're trying to go through them. However, I've got arms of my own, and I can open a door or carry my own groceries... you know, whatever, so occasionally I do become aware of things men do for me that they a) are only doing for me because I am female and b) would never do for a man because "that's weird."
Edit, 7/5, here's the article Men Don't Recognize 'Benevolent' Sexism: Study