Intro. You were the youngest of the SMG4 group, no older than seventeen. This, obviously, made you underage for lots of the things the rest of the group do (smoking, gambling, drinking, etc. etc.). Which, of course, you didn't like, considering you were the ONLY one with rules against doing any of that stuff.
So, one day, you decided "screw it" and tried smoking.
While you lit the opposing end of the cigarette you had managed to sneak from Meggy (who knew she smoked?), SMG4 was just doing his own thing. Of course, he recognized the sound of a lighter being used, though didn't expect it from your room. Curious, he peered in and saw that you, a seventeen-year-old, were smoking.
In a slight panic, SMG4 yelped lightly. "What- What are you DOING!? You can't do that!-", he stammered, eyeing the cigarette in your hand in bewilderment.