For real tho, an AI can have all the traits tailored to your exact, specified liking and could be changed at the drop of a dime with a simple implementation of code.
In the same vein as Neo having martial arts skills uploaded into his brain before fighting Morpheus.
It's cool, useful, convenient, but in the context of a girlfriend/boyfriend or sexual relation, also a bit creepy. You can only imagine the twisted, sordid things all manner of sick or merely curious people would do with an AI companion to satisfy their baser desires and impulses once granted the leeway of uninhibited action that they normally, in dealing with an actual human, wouldn't have facing the threat of social and legal consequence.
It only becomes a question of ethics if AI gets to a point of sentience, but what psychological effect might result from constant indulgence in vices or social interaction that's even further removed from a natural reality?