That's more of a Catholic thing. The Mormon church doesn't have altar boys the same way that the Catholic church does.

Also, as a rule children aren't allowed in the temples, it's mostly teenagers andadults.

Lastly, and this is pure speculation on my part, the leadership of the Mormons are allowed to get married and have kids. I think that generally reduces pent up sexual urges with no outlet.

Source: I grew up in the Mormon church.