I admit with Ruto, her feelings for Link are far more romantic than Zelda or Malon period. Still..Link didn't seem interested in her in that way at all. The only proof that
OOT/MM Link is heterosexual is the Cremia hug and that supports more for Link being with Malon if anything. But back on topic: In a future Zelda game, the whole boyish innocence thing will have to be scrapped if we as players are to believe that Link can get a girlfriend of any kind