The Cat's Meow by ferretbaby (Xmen 1st Class AU fic)

Some kind, generous angel had slipped a packet of condoms under the door. Their shadowed feet seen walking calmly off down the hall.

Huh.

It had to be the goddamn condom fairy, who was real and had bestowed her mercy on Erik this once. Forever he shall prey to this kind, benevolent deity. All hallow be thy name and shit.

Erik’s pet cat, Charles, gets turned into a human— mostly human. The brotherhood flips its shit in a hilarious way, Charles wants to adopt all the young mutants in the world as his kittens, and Erik’s a little unnerved that his former-cat has decided thy should be mates. THE BEST CRACKFIC IN THE WORLD. THE UNIVERSE EVEN.