it was either here or tumblr, and i thought it was roseluck but i looked through her tag with a few searches (roseluck, safe, -solo) and (roseluck, comic, safe) but didn’t see it.
It was a scene parody of one of the episodes in s1 or s2, so long time ago.
I’ve checked all over Derpibooru with those same tags plus more in different combinations and no luck. I dont see any comic that looks or sounds like that. As for tumblr it’s a lost cause looking for a specific post on tumblr. Sorry for that, if you’ve any more info it’d really help.