"Indian Summer" is a short story by Erskine Caldwell, dealing with adolescence in the Southern countryside and an early, ambivalent sexual experience.
The creek is not the best place for the purpose—the waters are yellow, the floor is made of ankle-deep stinking muck and it is also full of dead tree limbs, some of them very sharp on bare feet.
The two accuse Old Howes, a farmer whose land is nearby, of deliberately filling the creek with tree limbs in order to keep them away, since they are scaring his cows.
The newcomer turns out to be Jenny, Howes' daughter who is a year or two older than them and for whom they bear a grudge for having "told tales" and gotten them punished.
Jack, however, recalls that when they did it to a coloured boy named Bisco they came close to drowning him, and suggests to mud-cake Jenny instead.
Despite Jenny fiercely resisting and kicking Jack very painfully in the stomach, they manage to get her clothes off and proceed to cover her with stinking mud.