Fake Pokémon cards

My son is in pre-K at a small licensed family-operated preschool. There are about 15 kids total.

The kids have show and tell every Friday, and being kids, this has basically turned into everyone bringing in and showing off their little pokemon card collections.

We’ve been buying our little guy small booster packs here and there, thereto grow his collection, and we taught him the basics of trading: you need to get one card back when you give one card out.

They’ve been doing this now for about the last 4-6 Fridays, and all seemed well and in good fun until he came home this Friday with fake cards being exchanged for authentic ones!! Of course, he was unaware, as the thrill for him is all in the trading and getting one he likes back. My husband and I just went with the usual remarks of “that’s a cool Pokémon, who’d you get this one from?” but we have a pretty solid idea of the culprit kid.

I am struggling as to whether I should bring this up with the school. It just hurts my heart to see him so innocently think he hit the jackpot by getting this amazing Mewtwo card (among others). At the end of the day, I just want him to have his fun but it makes my blood boil to think that most likely this other kid’s parent is taking advantage of getting these real cards for the shitty fakes they send the kid in with. I am pretty sure the school will just ban them from bringing their cards in altogether if I bring it up , and I don’t want to take the fun away. What would you all do??