Is there anyone in the other person's family who could be an ally in this case? Especially if you are worried about the breaking-up and aftermath. The relative could give you some idea how to break up, or if there was ever trouble in this area. The relative could act as a shoulder to cry on for your other person, and keep you posted if needs be about his mood, etc. If that isn't the case, from what you said, perhaps you need to ask what your options are to the constabulary. An order for protection, etc.? Also, when you talk about a public place, it could be at a mall where you could get off by yourselves, but public enough for you to call for assistance if needs be, but God forbid.