From my understanding of how modern AI systems work, I don’t think it would be able to get “bored”. Its reward function would involve being the best possible companion it could be for you and only you. Moreover, it would have an algorithm designed to figure out all your desires and get its rewards by fulfilling them. Doubtless, if this becomes a reality, there will be all sorts of personality types available. From subservient, to dominate, to difficult to please, etc. etc.