Asking for something that you have not been invited to ask for IS NOT POLITE.
Have you pro-polite-enquiry folks been following the advice about how to 'politely' get a woman to take off her headphones so that you can hit on her? https://www.theguardian.com/science/brai…
There are a lot
of men who think that as long as you aren't pointing a gun and screaming and swearing, crossing a stranger's boundaries to request sexual services is 'polite.'
It's not. It's not polite at all.
Instagram-woman appears like she might be sexually active. PHOTO thinks that since someone else has her, he's entitled to her too. PHOTO is not polite, he's a potential rapist.
If you don't know how this works, I'll tell you.
If a woman offers
you something, being appreciative is polite. For instance, if she posts a picture of herself on instagram, telling her that she's pretty is polite. Even telling her that you look forward to her posts, that they brighten your day, is polite.
Asking her for something she hasn't
offered is NOT POLITE. So when she posts her pic, telling her that she should show her tits, or that you want to fuck her face is NOT POLITE. Telling her that you want to jerk off into her used underwear is NOT POLITE.