We’ve been together for 15 years but I have no idea how to sexually arouse him. He avoids the question & talks around it. I know he watches a lot of porn & he spends a lot of time looking at the nude pictures of every woman he’s been with. I wonder if he’s not excited by me so he can only have sex with me after looking at these things. Is that what it is? If not, how can I try to compete?