Language and slang change all the time and teens are great at picking up things to snicker about. I've spent a couple years with myy teens and a toddler and I forget how many times I've had to stop them teaching the little guy a new phrase.
Can you say mother fu - - - Dad weren't doing nothing wrong! He just wants to learn and we're totally helping him!You're no fun.
I'm amazed at how surprised my students are when they say one of the teenage "catch phrases" that I'm supposed to be too "old" to understand and I call them on it. They look like their whole world just tipped on its axis.