I sure know I am.
Here's how to combat it:
When your peer group starts to giggle and crack jokes like a group of middle school students over something like the word "sausage" being mentioned, simply do this:
Say "Hey! That's funny! Because 'sausage' is slang for 'penis'! Ha ha!"
Or, if the group starts to do that "gay play" thing. You know, where someone in the group who is obviously heterosexual insinuates that they are homosexual in a non-demeaning way, simply say:
"Hey! That's funny! Because it insinuates that you are gay! And you aren't! Ha ha!"
Nothing takes the wind out of these folks' sails like removing the billowy veil of insinuation.
And the key to this is that you have to have an upbeat tone to your voice, not a mean sarcastic one. You have to pretend like you are innocently just getting the joke and explaining it to someone equally innocent.
After a while, the stupid double entendre and gay-play jokes will stop, at least around you, because you are NO FUN anymore. You always run the risk that nobody will talk to you anymore, but that's a small price to pay, really, to rid yourself of people you really didn't want to talk to anyway.
Glad I could help.
Addendum:
You can also use this technique on overdone pop culture references. You know: those people who believe that the HGTTG and Monty Python are the ONLY pop culture references worth making. The kids seem to get stuck on Monty Python and HGTTG these days, and the phase lasts way longer than it should.
Simply say: "Hey! That's funny! Because it's in 'Monty Python and the Holy Grail'*!" (Same innocent style voice as above)
* insert the name of the appropriate pop culture reference, of course.
Glad I could help again.
I might try it.