How would you not hear her teaching?

Disrespectful. That crosses boundaries if you didnt want her there.

probably just move, let the girlfriend have the place.

I predict the next FML from this person will be that they were wearing headphones, watching porn, and distracted and someone walks in on them while OP has the trowser snake in hand… But seriously why would you need the volume up so high on porn that it was obvious from an adjacent room? It’s not like the story is hard to follow and you cannot miss a single sound. I have nothing against porn or self gratification when you are alone. But if there are roommates then either be quiet (and keep your door closed and locked) or check if someone else is there. There is always the possibility that your roommate (or their girlfriend or boyfriend) are there somewhere within earshot. Oh and there have been FML’s about the home stereo being linked via Bluetooth to the porn that another OP was watching (while using headphones) and being told by the Dad that “they need to talk”. So bear that in mind…