Only pokemon fell in love in the anime like Buneary is in love with Pikachu and Wobbuffet with Kirlia.
Nidoran male x Nidoran female in " Where Thou Art Thou Pokemon "
Grovyle x Meganium x Torpius in " Odd Pokemon Out "
Meowth with Meowthsi in " Go West Young Meowth "
Magnemite x Pikachu in " Sparks Fly for Magnemite "
Totodile x Azumarill in " Love, Totodile Style "
Those are the ones I remember off the top of my head.
And when did Casey show any signs of liking Ash? oO
Never, because Casey's too mature to play the eternal crush game.
I say this considering Casey's the only 10 year old who looks 10.
I WIN!
A NEW CAR-AH!