"The first time I smoked weed was with Demi and Miley. I must have been 17 or 18. They kept saying, “Try it! Try it!” so I gave it a shot, and it was all right."
Joe Jonas is three years older than Miley so you can do the math. The fact that she was peer pressuring the guy is something else. I'm sure she will come out today and say something like Joe got the dates wrong and she was much older or she doesn't remember that because you really don't want to be the person who was smoking pot at 12 or something unless you really want that Kneepads story later in life.
Another thing to be gleaned from the interview is that Joe says he lost his virginity at the age of 20 although he was doing everything else before then. He also says he started dating Ashley Greene at the age of 20 and that it was his first serious relationship so there you go.