Should I let management know a swim instructor is taking pictures with kids on his personal phone?

Long story short, I work at a swim school and an instructor is retiring, and he’s been taking goodbye pictures with some kids, and then asking the parents to take another one on his phone. I’m assuming the best intentions since he’ll miss the kids he bonded with, and he’s beloved by families, but I also feel like it should be common sense that taking pictures with kids under 5 on a personal phone is inappropriate, but he might genuinely be clueless (because he’s kind of the type). I feel a little bad for wanting to let management know, but is would that be the responsible thing to do? Does this seem like an overreaction? (For even extra context, he also thinks Trump is doing a good job).