Option To Add Spoiler Description

Some of the MDLer's generally add a second layer of spoiler as comments in order to protect other user from spoiling/ruining their experience.

This is generally the first comment of the post. But as more people starts commenting on it that comment gets hidden at the bottom of the post.

So it would be very useful if we could prevent this hiding of the so called "spoiler description".

The can be implemented in one of the following ways -

1.  We can leave some text at the top. This will be more of like a post title.
2.  We can modify the text "This post contains spoilers. " to a custom spoiler description.
3. The original poster if somehow could pin some comments on his posts.

 For both (1) and (2) there should be character limit on the description text.

PS - Just a random suggestion not a compulsion , I know this is a bit tricky. And won't be required by most of the users. It just came to my mind so I thought I If could share it here.