Kaa and Mowgli have a secret affair once a year where Mowgli secretly leaves his village in the middle of the night just to visit Kaa under that very same tree (from the second encounter) and constantly repeat the same sensual ceremony where Kaa hypnotizes him, lets his own body be under Kaa's control as he strides across his coils in the shape of stairs, loops, and slides until he's wrapped up nice and tight which is finished off with a sensual kiss and the two sleep together.