Is Deception a good thing or bad thing?

My parents raised me strictly hat deception is a bad thing but that rule has been eased a little bit. It is just like learning in school. For example I was taught to never start a sentence with but or because. But then that rule has been eased so I can start with but or because(see what I did there). Then again using deception makes you a more untrustworthy person and making finding business with others hard and potentially screw up your life. On the other side it could help you. For example your significant other asks if what their wearing makes their butt look big. You could say yes or you look lovely, without lieing. The you look lovely option sounds so much better and it’s true but your not answering their question. Then there is when you get stuck in a tight spot and it will only get tighter if you truthfully answer the question but if you use deception then it will get less tight. That example seems very lopsided but if you completely avoid the question then you will just make more of a problem for you. My thought on deception is not to use it unless you know when and how to appropriately use it. Also it can either be good, really good, or really bad.