The only real reason that xenophillia is frowned upon by some is because in real life, there are no species of people besides humans on Earth. If there wer Rainicorns or talking candy peope or frankly ANYTHING sapient other than us, rest assured humanity would have been breeding with them since the days before written history. It would be seen as normal. And no one would care. Because they're both consenting adults that just happn to be different species.
Just because something has the shape of an animal, doesn't mean it is one. It's all about sapience. nly the most xenophobic of people would have a problem with interspecies romance, as long as the requirements for intelligence are met.