Seeing your underwear

Man, I suck at formulating questions...please bear with me a minute!

We all know scenes in anime/manga like that: Protagonist-kun can see the underwear of Girl-san, in which context whatsoever.
Since I know there are a lot of girls on this platform (minority dude here!) I'm interested in two things:
1)Does it even bother you if something like that happens?
2)Would you like to be notified about it, like "madame, people can see more of you then you might like" (because we all talk like that, right?

For me this is of interest because I'm a writer (kind of?), but often struggle with realistic reactions of women, so I would like some input on that topic. I remember "back in the day", when I visited a girl for the first time (not dating). She was going through her drawer, looking for socks or something and pulled out a bra by accident. I immediately closed my eyes, since for me this was a big thing. But I wonder how girls/women think about it.

And just for clarification: No, I'm not interest in the underwear your wearing right now. No, I don't want to chat with you or something like that. Yes, I have a girlfriend, but she is so open-minded that she is next to useless for me in regard of this question...:(