Stalker - no doubt! Yes, carry mace. I'd say, "You're a pervert stalker, stay the F away from me, do not speak to me, do not look at me." You could notify police, he could be harassing other girls too. Maybe they talk to him and give him a scare, then there's a report on file. Trust your gut - don't tell him you carry mace unless you're spraying it in his face and run for help.