1. Don’t use expletives in general.
While it’s at the discretion of where you are and who is around you, shouting expletives in a relatively conservative Muslim country is offensive. I would place this under common sense, but it’s official as well. This goes for using expletives towards another person. While tourists may not be aware, I would place long-term residents as those more likely to commit this offense. It’s not to say I don’t curse (if you know me, you know I love a good f-bomb), but I choose where and when I say it, based on my audience.
If you choose to use bad words in public, know that the maximum sentence can be detention for a period not exceeding one year or a fine not exceeding 10,000 AED. The fines escalate should you insult a public official. (Article 373 of the Penal Code).