I was raised similarly. I almost never curse (I prefer curse over swear) vocally, unless I am certain I won't be heard (usually typing it). It's nearly a celebrated event anytime I am either obligated to use any bit of vulgarity (like going to see the movie Jackass in theaters, and my sister bore witness to my conundrum), or sometimes when I talk to myself or vent. At those times, I get a bit creative with my curses.
Odd thing, since my teens, especially when some of the bullying I was receiving (oddly enough, more from girls by then) was getting a little out of hand, I've been encouraged to let my language barrier loose, and curse like a sailor if I ever needed to (with permission of the C-word even, if it really called for it (never needed to use it, with respect)). However, I think I'm better off minimizing my vulgarity. It allows me to be more creative with my insults/threats, unlike most foes I encounter which go off on "WHAZZUP BITCH!" tangents in their crappy attempts to intimidate or threaten me. All I really need to respond with is a 'Bored Veteran' "Are you done?" (in a bored manner) and continue minding my own business. Most-any other time I would curse intentionally, I would have a time and a place for it to be a precision F-strike with some of the best comedic timing necessary to even get my intended target laughing.
I think any time you read any vulgarity in my posts, it's how I would casually say them in regular conversation. How I post is essentially me uncensored.
EDIT:
I think the only curses you would never hear me say would be anything relating to cursing God out. Too much respect for the dude, despite all the crap I've been put through.