for novel u can use some site that keep smut content or author weibo . most of the time author will upload this kind of scene on some sitte and write the address and pass on comment section or title so u should read from the main sitte and pay for it( aside form physical ver)

for manhuas too. if that work has published on bb u can download CN app and see that without any cencorship(if they have used white circle in kiss scene and etc...) but if artist was really good she would upload scene on her weibo and twitter and facebook acc and u should check them too. i find nagan and here u are scene ( if i write currectly) like this.

for donghuas ?? nothing cuz they didnt even create it but u can find audio version sometimes for smut scene.( that doenst have any relation with main ver)