Yeah, pretty much. You take someone who has what they see as a perfect life, but one without sex or with unfulfilling sex, and you introduce some reason for them to have sex with someone who's good at it. Maybe they're being blackmailed or persuaded - anything that makes them feel like they need to have sex in order to return to their previously idyllic life. Then, as they have more sex, they find that they enjoy it, and slowly start to prefer sexual side of their double-life to the one they used to think was idyllic. Time passes, and they end up fully engulfed in a life of wanton sex, abandoning the life they were trying to save in the first place.