My dad found out when we were all in Vegas for my 22nd bday. He's a smoker but he was cool about it. I felt bad, but he understands I'm a big boy now.

My mom on the other hand, can't stand it. She knows I smoke but I dread the day she sees me with one in my mand.

Tell them. Remember it's the point that they know, not that they'll be disappointed. They'll appreciate your honesty.