Christian summer camp is strenuously anti-flesh. They want as little as possible on display. Since they are basically running an evangelical kennel for high school horndogs, they must keep lusting at bay not only to please Jesus but to maintain some semblance of public order.
Every Christian camp enrollment form states “one-piece only for girls,” usually in those exact words. Sometimes they even add “two-piece swimsuits” to the What Not To Bring List just for good measure. All bits must be covered by law but Christian camp adds an extra step and makes sure all female stomachs and backs are covered as well…covered by thin…wet…spandex, that is. The logic follows that this extra fabric cuts down on lusting and pleases God or something.
The one-piece swimsuit rule implies that boobage is better wrangled by a one-piece than a two-piece, but this is categorically false. Whilst laying out on one’s fabric-covered back, side cleavage oozes into armpits more copiously in a one-piece than in a bikini. Christian camp does its darndest to keep lusting at bay, but gravity always wins.