Is he being rude, or is he just shy?

A few weeks ago, a boy I had been trying to get to know better added me on Facebook. We are in the same class in college, and I have been smiling at him for a few months. I didn’t know if he knew my name so him reaching out online was a pleasant surprise. I sent him a message soon after, hoping we could chat and maybe meet for coffee, but he saw my message and didn’t respond. There has been no communication since and I am confused. He added me, and I presumed he wanted to chat, so ignoring me is rude as well as hard to understand. Should I ask him about this in class, or wait until he messages? Maybe he’s shy and just needs to work up some courage. What do I do?
You should do what you should have done in the first place: say hello in person and ask him if he’s interested in going out for coffee. Relying too heavily on social media to communicate makes no sense when you see this person in real life on most weekdays and can simply focus on a human connection face-to-face. Introduce yourself, tell him that you were glad he found you on Facebook, and find out if he really wants to get to know you better. If he turns you down, at least you will know what this is about. Why lose sleep by speculating?

My girlfriend has a horrible habit of laughing out loud in movie theatres and doesn’t care that she disturbs everyone around us. She thinks I am ashamed of her when I ask her to be quiet, but I am just being polite. Am I wrong?
You have told her what you think, and she has chosen to be offended instead of examining her actions. If you don’t enjoy watching movies with her, choose a more acceptable activity. This is just a question of adjusting to individual quirks. Some people are more sensitive than others, and that’s all.