If a user deliberately clicks a post that is marked NSFW and blurred in their feed, I think the assumption should be that they intend to see it and are doing so with the knowledge that they have made sure their boss isn't around or whatever. It doesn't make sense to me why you would need a second tap/click to actually see the thing that you tapped/clicked. At least, that is the behavior we have in the PieFed UI, clicking into a post or tapping the blurred image unblurs the content.
The rule that we try to stick to is that anywhere that the user is presented a list of posts, the user's blurring settings should be applied. That even applies for a community page for a community that is marked as NSFW as a whole. That is because a community link might look SFW based on the name, but turn out to be NSFW. Community links don't have the NSFW label on them in the web ui, so the user can't always be considered warned that they are about to open up something NSFW.
Anyway, that is just, like, my opinion man...