I don't know. If you don't have any issues with them having sex and not being married then why worry about it. I do think you're really nice to be helping them out.
I suppose you must be well off since you're paying for all his expenses and he doesn't have to work.
In my honest opinion I think college is a full time job. If they have to work to eat then they need to file for financial aid and get loans and any sorts of scholarships they can so they don't have to work.
Full time college and GOOD GRADES is their job. Not enrolling in full time school then going to work instead of going to the library to work on a research paper or reading assignments several times through so they can understand the material well.
So when our kids go off to college they will fill out paperwork for all the financial aid they can get plus they'll try out for all scholarships they might qualify for. I do not want them to work.
They will also live on campus with a meal plan if they are out of town and can't live at home. That way they have full support of staff in the dorms and can turn to them if they're having any issues.
I lived on campus in married student housing, I had a child, and I paid less in rent than almost everyone else in town. I also had all bills paid including phone and TV. I paid nothing extra. These apartments are still the best price in town. I went back to Stillwater the other day with a friend and she was looking into housing for her senior kiddo. I was glad to see that the campus housing is STILL less than anywhere else in town.
AND if they get any financial aid or scholarships their rent and any bills come out of that BEFORE they get a penny. When I lived in Stillwater I had them hold out my rent for the whole year, fall, spring, and the next summer's rent. That way if I had zero money my rent was paid and at least I had my apartment.
Campus housing might be a possible idea for this couple if they want out on their own. I don't know where they're going but if there is campus housing they might even be able to get a meal plan in addition to rent and then you have one monthly bill to pay for him. If she's working enough she can pay for herself/half of the rent.