I want to limit my roommate's access to the WiFi
Why do you want to limit access to the wifi?
He watches ugly porn all the time and I want to stop him from making me sick with that kind of content
I hear you, but if he pays for it, then you should let him use the internet as he sees fit. You should be more understanding and perhaps ask him to turn the volume down. Otherwise you will be a control freak and disrespectful of other people.
No, it shouldn't be up to him. I pay a shit load for this internet so he should not use it at all.
You should talk to your roommate and ask him to watch porn in his private space with low volume. There is no point in fighting over such small thing.