PLEASE Use Good Form!

I can't stress enough how important good form is on ANY exercise!
This morning, my training partner, another guy and I did chest. The other guy wanted to do the same weight my partner does, but his form was NOT GOOD! So I made him go lighter and do the exercise correctly. NO SHOULDERS PLEASE! I think I may have been a little harsh about it though, I told him to what weight to do and I forced him into the correct body positioning.! It helped!- He then had good form! I don't know how he wiggled his body into some of those positions, but he was just going hurt himself or develop more huge muscle imbalances.
The lesson is: If your training for bodybuilding, be sure to use the correct form and muscles. The amount of weight doesn't matter if you can't do an exercise correctly!