Young gambling will always be around
.
Some of my fondest memories in high school was playing cards in 'Legal Studies' just because how much the teacher disliked it (legal studies + gambling? he he). The bets were trivial things like pencils or candy but it was fun. By far the best memory was when my mate pulled out a roulette set and we started playing...the ball was so loud
. The teachers face...it was priceless.
Anyhoo, I don't think there is any harm in it. Gelats can't be refunded (as far as I know) so you're not truly gambling for money. It's just in-game stuff and enjoyment (and bragging rights).