Tengen and Rengoku are in a part of a river that doesn't move much due to some rocks blocking off the stream - They are washing themselves. The water goes up an inch above their hips, the water being the only thing that covers their more private areas. Mitsuri talks about how much she loves everyone to the other Hashiras.

Misturi: "WAA YOU'RE SO CUTE I LOVE YOUU" Giyuu: "mhm.."