Long distances can be managed. My wife is from Cuba and it was almost 1.5 years after we were married that we were living together. Most weeks I would get one email from her and would call her once a month for an hour. I would go to see her, one week at a time, about 4 times a year.

If you or he do not mind driving 2.5 hours is a breeze. It has nothing to do with distance it is your level of commitment. Letting him sleep around will not help in this regard.