A very punny conversation for you to use:
What Do you say to one of your co-workers who works with you in the fire department when he says that one of his old girlfriends who cheated on him is now back in his life, and he wishes to go on a date with her?
Your response ” So an old flame is back in your life?”
He then says ” Yes and I rally hope I wont get burned again.”
You can then respond by saying ” I think by now you should know what happens when you play with fire.”
For more punny conversations: Punniest Book