I also hate when in the Trailer they add behind the scenes when the drama is not finished yet. I HATE behind the scenes bc it kills the fantasy of the drama.
I donāt watch trailers at all until the drama is fully subbed and I see the ending of all episodes.
I sometimes watched shows that showed the end of the next episode as the beginning for whatever reason so it was not exciting anymore. If possible I use the ādonāt show preview/intro/outroā option if there is no such option I either do it like you or stop/skip it manually.
Sometimes they also show cut scenes in the summary on the beginning, e.g. in crime shows they show ugly stuff they did not show in the full episode so I try to avoid that as well because I donāt want to see suddenly ugly/violent scenes.
I havenāt seen a show where they show the ending of the next episodeā¦ that just sounds crazy lol But then again I usually turn it off at the end and donāt bother with end credits - only did it for one show with a great end credit song and luckily no spoilers.
The funny thing is that previews are often VERY misleading, matching dialogue with scenes that donāt belong to it, or you may see a scene of people kissing or whatnot and then you find out that it was only a dream or a fantasy.
Good to know, irmar, and really not all that surprising. Even the final scene in an episode (prior to the previews) is often misleading, so why should I not expect the same from the previews? Thank you for bringing that to my attention. But now, assuming that the previews are not 100% misdirection, Iām still left with a problem. Am I seeing whatās NOT going to happen, or do I now know what IS going to happen? Oh, the confusion that may take hold in my poor mind! Iāll give it peace by continuing to avoid the previews. 
And since the only way to find that out is to actually watch the upcoming episode, the show makers succeeded in their mission after all! 
yeah they usually show those scenes AFTER the end credits finish rollingā¦
I just finished watching a C drama where the two main characters hate each other in the beginning. One of the first scenes shown in the opening credits is their wedding that happens in the final 5 minutes of the series. Just a slight spoiler.
Yes, I saw a chinese drama where the lead was a princess who had fled when her kingdom was invaded and she now led a simple life. In the opening credits you saw her in a royal weddingoutfit and a total spoiler and so unnecessary.
I just watched Kill Me Heal Me and WOW the opening preview spoilers are sooo irritating!!! 
You guys are complaining about spoilers in Cdramas, damnā¦ I never watched a Cdrama though but u should still feel lucky enough that you donāt watch Indian Serials.
The entire series is just spoiler-spoiler. A half an hour episode on top of that, theyāll take first 5 minutes explaining what happened in the previous episodes and then theyāll take 10 minutes at the end of an EP telling what will happen in the next episode titled āKal dekhiyeā (watch tomorrow) and as if thatās not enough, theyāll come every Saturday Sunday with their 1-2 hrs āMaha episodesā(Grand episode).
And the biggest thing. All stories are entirely the same which is fight between the Mother-in-law and daughter-in-law and thatās it.
Guys, be happy!
Then there is no possible spoiler, since everyone knows what will happen, LOL!
You still donāt know who will survive ā¦
everyone should experience this at least once! 
nothing like a solid saas-bahu serial