My boyfriend is having trouble ejactulating ? before we got together he was watching a lot of porn..could this cause him to have the problem?

Get doctor checkup: There are many reasons why guys have problems ejaculating - in the younger population, it's often from marijuana use. As guys get older, it's more often from other diseases like hypertension and diabetes. Your bf needs a thorough medical checkup to make sure nothing physical is going on first, and once those things have been ruled out, you can talk about behavioral causes (anxiety, etc.).

Stop the porn: It is possible that your boyfriend has an addiction to porn and that it has become a conditioned stimulus that he needs to achieve sexual climax. Assuming no medical problems, it would help for him to speak with a sex addiction specialist.