That question hits a nerve, honestly. I've been in a book club for a decade, and this debate pops up like clockwork every few months. My own view has shifted over time. In my twenties, I'd have scoffed at the idea—it's fiction, it's a safe fantasy, it's not real. But after being married for a while, I noticed a pattern in my own reading. When I'd binge-read those intense, possessive-alpha-protector books during a rough patch with my husband, it wasn't just escapism. It was actively comparing my very normal, flawed partner to these idealized fictional men who always say the perfect thing. I'd get irrationally annoyed at my husband for not 'reading my mood' like some romance novel hero supposedly would. That felt like a form of emotional displacement, for sure.
I don't think it's 'cheating' in the literal sense, because there's no other person. But it can become an unhealthy coping mechanism if you use it to check out of your real relationship and feed resentment. The key for me was noticing the 'why' behind my reading cravings. Now, if I'm craving those super-intense, 'he burns the world for her' stories, it's often a sign I need to communicate something in my own life, not just live vicariously through a book.