When you KNOW that the intention is not benign, don’t take it into action.
This is the least you can do.
For example, it’s true that the reason why you wanna tell her that may be becuz you’re in a mood of sharing, but clearly you know you’re actually looking at the possibility that she might share it with someone else. Realizing it should stop you from doing it, though it seem to be a harmless gesture. Still, heaven and you know what you were really thinking.