Guys, so I'm doing this internship program and like I have a roommate right.

Well, how would you feel if you had to listen to her videos? When you have a roommate, you have to think about them too. I think you should buy a good pair of headphones. And, I think she should've asked a bit more politely, something like "can you please put in headphones."

I am a patron of public transportation, and I consider it common courtesy to use headphones when around others. I figure if I don't want to hear someone else's music, other people don't want to hear mine. I guess what I'm saying is "put yourself in her position."

What because she doesn’t want to hear your YouTube video ?

That seems like an overreaction. All she did was ask if you could put on headphones.

Just put on headphones I don't see the problem.