I've always wondered why chivalry should be limited to men helping women. I, for one, can honestly say that I've held open doors for just as many men as i have women. Of course, most of my door holding experience comes from waiting for my ride after college lets out. I'm just there, so i may as well open doors.
I can't say the same for coat borrowing. Although, I've only borrowed out my coat once (to a girl) and most guys i know of aren't particularly succeptible to the cold. With that said, i can't really see myself doing anything different for a freezer-baby girl as i would for a freezer-baby guy...unless its below freezing. Nobody gets my coat then >_<.
In the end, if chivalry is simply manners, then why doesn't it apply in all situations?