Ok so if you want big bulky muscles...do high weight low reps in the gym.
For tight long muscles do low weight high reps.
Im not sure if its fat or just his big muscular pecks...little confused.
If its muscle...do what I said above. If its fat, still do the low weight high rep routines but also try whats called circuit training or something. If he keeps his heart rate up while he works out and goes from machine to machine without stopping for too long it will also help burn more calories.
There are many ways to work out the chest. Incline bench, decline bench and tons of dumb bell workouts. Even just doing push ups with your arms further apart than normal will focus more on the chest and less on the triceps and shoulders.
Unless you are speaking about the tissue that develops inside the nipple causing them to look.....erect...all the time...that I cant help you with.