ALL CHARACTERS are over 18 and consensually
Two panel comic
Katara and Zuko from avatar the last airbender
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Panel 1
Zuko finds Katara bathing in a lake/stream
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She's embarrassed
He's turned on. He has an ahegao face
Panel 2
Zuko is doing Katara doggy-style
She's leaning on the rock behind her
He's standing calf-deep in the water
Both are nude and having a good time.