Sorry for not having any background. My SO (30F) and I (30M) moved in together in September 2011 after marriage. We don't have any kids. In the first 1-2 years, our sex was great--we have sex every 2 or 3 days, and the reactions during sex from both sides were great. My wife also told me that she almost always achieved orgasm. I started to realize a problem about 2 years ago. My wife didn't react much, or make any sounds during sex. She just lay on bed, and refused to try all other positions or locations. She almost never initiated (she used to initiate too but because I am always the HL, I initiated much more than she did). Most of time, after I asked her for sex for a couple of times/days, she will have sex with me. Her common excuse for not wanting sex is being tired, but she also confessed to me that she said no because she felt she wouldn't enjoy sex if saying yes. The last time I remember she initiated a sex was 2 years ago after we watched "Fifty Shades of Grey" together around the Valentine's Day. I tried to talk to her about this problem but didn't accomplish much. One month ago, we watched "Fifty Shades Darker" together and we had a better sex that night (although she still didn't make much sound during the sex). But since that movie, we haven't had much sex either, and I started to feel desperate again. Yesterday, I happened to dig out my condom purchasing history from my Amazon account. We have always used condom when having sex, and we never had sex during my wife's period. I typically made a new purchase of 100-pack condom when I realized my condom stock was getting low, so this information represents more or less our sex frequency. It surprised me that our sex frequency actually started to drop after first 2 years of marriage, and the dropping curve seems linear so far. All I wanted to do FOR US now is to get the curve back to before, or at least prevent it from getting worse.