This was rated teen; it should be a safe space for teens to engage in.
Parents shouldn't have to helicopter-mom over every single thing their kids want to do if an entire country's rating board has deemed it acceptable for them to do it.
Similarly, real life interactions at like.. a baseball game or camp site aren't "rated" by anyone either, that doesn't mean everyone has license to go full perv when it suits them.
At camp, kids might see some adult behavior or hear some language...heck the guys in the next tent over might even be getting in on...but if they wanna go swim in the pool for an hour or two the first thing I think about should not be "oh man I hope some older perv doesn't try to touch my kids".
Like I'm saying with camp- it doesn't mean there can't be adult goings on...but it is the adult's responsibility to check they are engaging with an adult 100%. Ignorance is no excuse and "I didn't know he was a boy.. or that he was 13" would not hold up in any court of law.