No, this is (unfortunately) not the beginning of a porn comic.
It's really late to make this joke, but I'd imagine a lot of the smashers were a tad confused when Lucina first joined the Smash mansion that pretty much everyone accepts as a headcanon (including me). I'd think she and Marth would get confused for one another often, especially by those who may not be too great at telling humans apart. And I know she actually looks really flat-chested in the game, but it's for the sake of the joke.
I might start making these little one-off AwkwardZombie-esque comics of moments Ravioko and I make up while playing Sm4sh. I have several in mind.
