Compulsive Porn Watcher
Make yourself hard again, if you've gone soft (I don't think so though!). Then put that cock ring on, or tie the rope/shoelaces at the base of your cock, tight enough in order to keep the erection.
That will keep you hard for a while.
Training's not over yet. I want you to stroke yourself to the edge of cumming once every hour until you go to bed tonight. Keep the cock ring and only take it off to sleep.
Tomorrow, edge one more time just after you wake up, and put the cock ring back on. Edge once every hour till you go to bed tomorrow night. No cumming allowed.
I hope that will teach you to remain hard at all times, and to be ready whenever your girlfriend wants to use you. You will not be cumming anymore without her permission.
And remember to not watch porn either. You know what's in store for you if you go down that path again.