lovinghalacha, if this issue does not concern you but is in fact about someone else I would tell you to stay out of it. That is number one. It is most complicated and by getting involved you can make it worse.
If it is about you, then I would speak to your parents and maybe consider seeing a therapist that can help you sort out your emotions. It wouldd be a good idea that you stop speaking to your relative for a while, that you take a break. If when the two of you are of marriageable age and you still feel the way you do, then at that time you should weigh the pros and cons of pursuing the relationship.