(I also sent this to you as a private message, but I figured I would also post my response for others to see as well.)
I actually never told my friends. It doesn't really come up in conversation. Some of them just kinda found out when I was on the front page of the Courier. (In the words of my friend, "I was going to pee and my mom left the newspaper on the floor and BAM I see you staring back at me!") Some of my friends still don't really know. I think that if it comes up, you shouldn't be afraid to tell anyone. Half of them will think you have some immune disease that causes you to wash your hands and never question you again; the rest will just back down and have no clue what you're talking about; one will have a family member with OCD (or have it themselves) and totally understand. From my experience, your friends just won't care that you have OCD--there's so much more to you than this illness! Unless it's really impacting your relationships with friends, you really don't need to be pressured to tell. If you want to tell, don't be afraid to. If your friends respond negatively, it's THEIR problem, and they're not real friends.
Oh, and about the jokes- They're no different than when hyper people are called "ADD," moody people are called "bipolar," or hypocrites are called "schizo." Most intelligent people realize that these stereotypes are different than the actual illnesses. (I stress "intelligent" because it really depends on who you're talking to.) Just know that most people who make those jokes have no clue what they're talking about.
I hope this helps!
~Caitlin