I think everyone has "cursed" at one point in time (although the definition of cursing is subjective), and if you say that you haven't, you're not telling the truth in my opinion. Cursing has a different definition to every family. To a strict family, you have cursed. But in your definition, you might not have cursed. However, saying that you've never cursed is like saying that you're not a sinner (sorry to get religion into this, I just think it applies to this context).
I know I'm overthinking this but yeah... That's my answer.