I've been writing erotica privately since I was a teenager. Many nights staying up late in random chatrooms made me a master at cyber sex, which then led to very fun experiments with phone sex. My first long-distance relationship completely relied on it. As anyone who has had phone sex will tell you, the best way to master dirty talk and dialogue in a sex scene is to practice it. My work uses dialogue as a tool to exposit the situation and to reinforce emotional connections.