I’m sorry, but I believe this to be an oversimplification. One can be tempted many times towards the same sin without sinning. We are to avoid all near occasions of sin, therefore indulging a thought or thoughts of committing a particular sin is, in and of itself, sinful. When you are the subject of a temptation, and you try very hard to put it out of your mind, you are not sinning. This is true, I believe, even if you have to contend with the same temptation over and over again.
I would agree that any sin in which you begin to engage, but disengage yourself from before completion, is still a sin, though, perhaps, less grave than if you had completed it.