Hopefully nobody here buys all the bullshit about how "sex isn't that important in relationships". In my experience and opinion, it is one of the single best indicators of where you stand with a plate/ltr/whatever.
Back in my bluepill days, I could never get a good reading of where I stood in my relationships. I had no fucking clue. I relied on what the girl said to me, which was vague at best, and horribly wrong at worst. Women will never really tell you how they feel about you. And if you ask them directly, you might as well shoot yourself in the foot. How many men have heard that they are "sweet, wonderful, supportive, understanding, etc..." only to be cheated on?
Sexual behavior is the quickest shortcut to what's in a woman's heart. If she wants sex often, is sexually open to you, and is very exited and engaged in sex with you, then you are doing it right. If you find your woman CRAVING you in the bedroom, then you are winning. Whatever you're doing is working.
Now on the other hand... unless she has medical or severe mental health problems, a decrease in sexual interest, frequency, and intensity is almost always a sign of big problems. At best it usually means she is losing her attraction/respect for you and at worst, this has already happened and she is getting sex elsewhere. While her words and hamstering may tell you that everything is okay and make excuses for the lack of bedroom action, her body will betray all those secrets to you.
This sounds obvious to me now and I question why I am making this thread. But as a bluepiller, I honestly thought I was a piece of shit for thinking sex was a huge part of a relationship. More than one girl shamed me into thinking this was true when I confronted her about our lame sex life. One of our tenants is to ignore a woman's words and pay attention to her actions. Sexual interest is as pure as it gets with actions. Use it accordingly. Don't let anyone convince you that sex is not an extremely, if not the most important part of a male-female relationship.