Pretty much when I say more complex rather than say just progressing from one scene to next and say having an in story objective to just initiate the scene, instead you have mechanics such as like a "exp system" or lust/mood levels that you develop by doing activities either sexual or non-sexual and sometimes events/circumstances change what would be more effective, like say touching a character sexually in front of another but hidden will be negative early on but when you've gotten her to become more perverted will be into it instead.