There are shove-head styles, banana styles, flex side styles and others that are consider cups. There are many undergarments that hold these in place and the web is full of both cups and undergarments.
The NuttyBuddy is a takeoff on the run-of-the-mill cup, and for some, it serves the purpose. A little pricey in my opinion .... but it serves a purpose.
The price of cups plus undergarments like - BIKE - CHAMPION- DUKE ATHELTIC and others are not that much - considering the protection they offer. The trick is to find one or a combination of cup and undergarment that works best for your son. So, I would suggest going to a few sporting goods store with your boy and looking over what's in stock. Look over the variations and purchase a few. Then by trail and error, your son should find something that accommodates him.
Now I know the cost outlay may be a few bucks, but figure the protection and choice that your son makes should be worth the money spent.
Here's simple suggestion that every professional makes when suiting up - liberally dusts the inside of his cup, and the undergarments holding it, with talcum powder. The talcum powder stops chaffing, eliminates the irrigation of the cup rubbing against the skin from sweat, and also prevents a rash developing in that region.
Another consideration of wearing a cup is your boy's understanding of the sport, and as a varsity player, he's prepared for a roster spot. AS he gets older and moves up in competition - this small detail does not go unnoticed by college coaches and by some scouts.