To me I think if you’re ready to marry this guy you should feel close enough to have open and honest talks with him about what’s going on. With my guy, I explained how I felt concerned and rejected with the drop off and my bf assured me it was typical for him for his libido to drop off and not me. I even asked him if it could be porn because I know that can cause lack of interest in many men, but he didn’t think it was the problem as he didn’t watch it much ( I have no problem with him watching if it doesn’t interfere with our sex life) I will say I’d have a problem with my guy paying for porn with cam girls, that’s a step too far for me and I think is a deeper problem, but that’s just me. Anyway , talk to him about it .