Hello, cherrykix. My thought is to tell the coworker you are there to work and have no interest in a relationship. Do not accept presents. If he does not get the message, ask your employer for help in resolving the issue. I do not see how this can be resolved without some tension. I hope your boss understands the necessity of making it clear to the coworker unwanted advances will not be tolerated.
7 Tips for Setting Boundaries At Work | World of Psychology
Being assertive: Reduce stress, communicate better - Mayo Clinic