We never get to see Simba and Nala kiss. Disney has made animal couples that baciare for years. Even Kovu and Kiara get to baciare although accidentally.Do te think that is because they just don't and never baciare as a couple?
Well Nala kissed him during the "Can te feel the Amore tonight" song it was probably all they could do because since it's a Disney movie and they're animali so doing too much of it would of made it awkward is my guess :P