Where do you live and how old are you to not know this? Seriously, I want to live where you live.
If someone is offended then yeah. The person offended should come to you about it first, but not everyone is comfortable contronting someone else. Especially considering how quickly people are willing to ridicule others over the internet. Alternatively, they could just be reporting for the sake of reporting.
Best bet is to just remove cursing and whatnot from your vocabulary while playing GW2. I swear all the time and let highly offensive comments fly without second thought but I turn that stuff off when I'm in the workplace or around my parents (and online gaming) and have been doing so for years. So it comes naturally to me to not let anything fly in GW2. Keeps you safe from bans so it's a good practice.