Well, if you say that you have a problem with the lack of sex, then you have a problem that needs to be addressed. 3-4 mo dry spells are not good. Was the sex always this seldom with her? Openness and honesty are always best. I would think after 7 years, the porn thing would have revealed itself sooner if it is an addiction. Is it possible that you are afraid of what her answer might be as to the reason for her activity? Good luck