OK, it's about the embarrassment, right, and some things are embarrassing to the point of not bringing them up? (There or here. And I know I've exceeded my quota.)
BOS-DEN. We arrive at the gate. Everyone gets up, including the couple in front of me. The usual wait. She has a blood spot on the back of her white skirt. There's a matching one on the seat. Both pretty obvious. The poor woman. Say something? Well, she'd probably rather know, and sooner than later. I tap the guy's side with the back of my hand, because it seems easier to approach him. "Yeah?" I try to discreetly look down at the seat. He freaks, in a sort of contained way, but in close quarters all the inside moves are pretty clear. So what was a "situation" becomes DEFCON [Whatever], and he's checking her out like one would a small child. The poor woman! She gets out of her sweater and ties it around her waist, and when we get to the door, the flight attendant lets her into the lav. The guy tries to go in, too, but the lady says no, she'll take care of it herself.
I mentioned this to a lady friend who told me that it happens more than guys will ever know.
An interesting thought (to me): Sometimes something's humiliating to the person who's humiliated, while everyone who's aware is absolutely empathetic.