Obviously, tease and denial (T&D) is fun for the recipient. No matter how many times you do it, he (or she, for that matter) will always want more. But if it is not fun for the teaser, or if it becomes monotonous, the teaser (you) will eventually stop doing it. You may even resent doing it.
I have always said, “Imagination is the key to sexual pleasure.” If you don't have the imagination you need to keep things fresh for the both of you, you will begin to look at it as a chore instead of an enjoyable activity.