>>725354920
I can't remember where I read it (Hyrule Historia?) but apparently the Zora evolved to look more human-like specifically to get along better with humans. The presence of secondary sexual characteristics like breasts, especially if they're faux-breasts, would thus imply that Zora women have evolved specifically to attract human men. In other words, Ruto's lust for Link may be biologically imprinted in her.