My kids like Eminem?!?!

I have 2 kids, one's 6, and the other is 8, they BOTH have Eminem on there iPods, and I mean, ALOT of Eminem. At first, I thought it was hilrious, especially when i saw how they dance to it. But then, Eminem has so much swearing in it, I dont think it'd be cool if, when I had guests over, my kids start swearin' like Eminem....Any suggestions? Hahaha.