Indeed, we modern people are incredible pussies when it comes to the more entertaining usages of certain words. If you applied today's political-correctness filters to medieval (or older) language, all you would hear was a single long beeeeeep.
I dunno...I'd imagine it wasn't too much different (barring the introduction of broadcast and other mass communication). There was polite, "courtly" speech and there was "vulgar", common speech. Just like today, you can go to any bar or playground or even plenty of workplaces and hear people swearing or using other language among their peers which would deemed impolite in other situations. In the same way, medieval citizens probably wouldn't call the local lord a fucker to his face or swear in church (or to their grandma) but they certainly did among peers.
How you talk to friends versus how you talk to those in positions of authority or respect is probably one of the first examples of "code switching" many of us learn as children.
