Funniest way to phrase a "Do Not Enter - Having s*x" door k**b hanger?

Question

I'm making one of those little rectangle signs you hang from a doorknob for my friend as a joke gift; I want one to say something along the lines of "Do Not Enter: I'm busy (having s*x)" but funnier. The other side is going to be something like "Come on in". Hopefully you guys get what I mean. What should the door hanger say??

Thanks!

Answer 1

busy (having s*x), return in 5 minutes

and

come on in and have a ciggeratte with us