is cloud 10 a drug? what is it?!

So, I was playing a game on my boyfriend's phone and he got a text from an unsaved number that said "sorry dude. cloud ten is sold out."
I asked him what cloud ten is and he told me he didn't know and he didn't know who it was.
he used to do pot and other things before we started dating...I don't approve of drugs at all.
i'm afraid cloud 10 is a drug or something...
can anyone help me out here?

thanks!
can