This problem has nothing to do with you. He’s been masturbating to porn for so long and has developed certain methods that have become ingrained in him. This is a problem, especially if he ever marries and wants to have children. The one important piece of information you haven’t given me is how often he masturbates. If it’s every day, or more than once a day, then I think what he should do is stop, wait a few days and then have sex with you. Hopefully, he’ll be more aroused that way and it might work. Of course if he feels pressured, then it won’t work.

The best approach is to try to get him to slowly wean himself of this habit. If he can’t do it on his own, then he should go to a sex therapist. And while you’ve been patient about this, you’re not saying that this is your final relationship, and if he ever has to find a new partner, it would be much better for him if he was cured of this. Since you seem willing to help, I strongly advise him to begin to try to solve this problem now.