For some participants, this is a major draw, away from parents' and teachers' watchful eyes, hanky-panky.
Not to rain on the parade. Parents shouldn't be too naive about it. Ask your child what else is going on during the down times, another opportunity to train their situation awareness.
MUN gives your child a platform to shine. If your child likes it, sky is the limit. You just need to find proper attire for him/her.