No chivalry here - chivalry was over on that one blizzard planet full of crazy people who dressed in old-timey armor and hung out in castles like weirdos! This here's just a boy who grew up being told to be nice to women and children and the elderly in particular - they're the ones who get priority protection and consideration!

That aside, the suggestion makes Manabu move a bit more, halt with a sudden flash of embarrassment as he realizes it seems kind of creepy to just stand there and gawk at a woman anyway?

"I mean!" His face flushes hot, but only briefly; thank goodness for cold blood. "Just to make sure if you do fall, you're at least not hitting the hard ground? So--"

So he's going to shut up before he embarrasses himself and just...take point while trying to not look weird about it, which only makes him feel weirder.