Yeah, Baskin Robbins would be considered bulking "dirty", but I'm talking about drinking a gallon of milk a day. That's not a dirty bulk. You'll only get fat if you're not doing heavy compound weight training. Otherwise, you'll gain mostly muscle, and some fat. This is how people bulk up. There is no other way. Even bodybuilders who care about six packs eat like pigs during their bulking season. Their six packs disappear, they get a little chunky, but then they cut down and get their six pack again, except this time their muscles are even bigger. Obviously, there is a more scientific approach, and you can make your bulk super clean, but for a young kid who has no clue about nutrition science, the gallon of milk approach is the way to go.