Meat sitcks to a grill surface if the surface is dirty, cold, or if we try to turn it before it is ready.
Start with a clean surface. Let the grill surface get hot. Don't try to turn the meat before it is ready. It will let you know if you watch. When the meat hits the grill surface they embrace each other in sort of a "hug of love" Leave them alone!! Do not disturb! After the "hug of love' is over they will release each other and the meat can be turned without sticking.
That being said, pam spray or a light coating of oil on the surface of the meat want hurt a thing.
There is only one Quality worse than Hardness of Heart, and that is Softness of Head.
Kool-Aid...Think Before You Drink