Now, I don't claim to know have read works where the characters do lose control, but I know enough from author posting in public groups, that they have uncontrolled sex or passion for each other. They have bare chested men on their covers (thank God I haven't seen any female nudity) or they all over each other. It seems to me that is all about sex and sexual immorality. The authors of erotic romance have no sense of morality and they love to play it out in the books. I can't even imagine a Christian doing the same. Our minds and hearts should be pure. Paul wrote to the pure God shows himself pure. He also wrote that nothing is pure to the wicked.
By the types of romance, you could pretty much tell who is pure and who is not. Sex outside is marriage against biblical standards yet those who aren't pure will write just that. My second book in series involves around my mc who became a victim of rape. Rape is not sex and it is all about power and control. In my story it is about revenge and the villain salivates at the thought of touching her and dominating her. It gives him pleasure, especially in knowing what it would do to his half brother Eric, Julie's husband. He had wanted Julie for himself since his half brother laid on eyes on her first. Hate and revenge drives Drew to rape Julie.