This happened yesterday but I'm finding it still playing on my mind.
I was in the Post Office sending a parcel when two teenage boys (they looked around 14 or 15) come in with a little girl (around 8). The boys pick up some sweets for the little girl and a drink each, then ask the cashier for a pack fo cigarettes. To my shock, the cashier gives them the cigarettes, and then the boy realises he doesn't have enough change (not even close!), so pays by card, and they leave.
I can't help feeling I should have said something. The boys clearly did not look over 18, and not having a clue about how much a pack of cigarettes costs suggests to me that they are new smokers. Should I have said something? Or is it none of my business and I should just let young people make their own mistakes?