If this guy isnt married and hes that young its def an issue. I dont think hes necessarily a bad guy, its just unfortunately guys like him are wired to be attracted to you. If he gets a simple reject from you, his brain will kick in and tell him hes a moron to keep on doing this. I’m sorry to put it so bluntly, but thats the way it works.
Miriam: Granted, it will be akward, but by nature its an awkward situation. It will be awkward for him too and he’ll get the message. However yoyo, if it does make you excessively uncomfortable, then have someone else talk to him. But he’ll have a lot more respect for your position if you say it to him directly. Otherwise he could be like “so i see you need to get your rabbi involved in my buisness” or smthng like that