Well, someone that lent you money is entitled to sue you to collect the debt by taking you to court. If you find the communications harassing, you can ask the guy to stop contacting you and if necessary, take out a restraining order to stop him. But that is just going to increase the chance of him filing a lawsuit to collect. Hope this perspective helps!
If it was a loan, you owe it. But it sounds from your post that it was a gift. He never expected you to pay it back until he got mad because you later refused to marry him. He can sue you (anyone can sue anyone), but he has the burden to prove that it was a loan and not a gift. Just ignore hus harassment. Do not respond to it. But be prepared to go to an attorney if you are served with papers from a lawsuit. You must respond to the lawsuit within the allotted time and in the proper method, or you may get a default judgment against you. It might be worth the peace of mind to go ahead and consult a lawyer now. They will usually charge a small consultation fee, but they can better address your actual situation. Good luck!
No attorney-client relationship is established with this answer. It is not to be considered legal advice, but is merely given to point you in the right direction and give you a general answer as to the law regarding the question you have asked.
The question is controlled by the laws of the state in which the transaction occurred. Each state has different rules. I am not licensed in NY nor NJ, so I cannot tell you those states rules. You should contact someone up there to get an answer rather than living in fear of the unknown. I would not post the specifics of the agreement on this website just in case he finds this post and attempts to use it against you.
This answer does not create a attorney client relationship and cannot be relied upon as a legal opinion as there are too many unknown facts to this matter to render an opinion at this time. Campbell & Grooms, PLLC http://www.campbellgrooms.com