Your sister's slut offers sex in exchange for helping her study

This aunt is screwing herself because she doesn't stick a stick in the water and is lost in class, so the last option left is to turn to her brother to see if she gives him a hand. He has no intention of helping her in the shit, but his sister offers her sex and then things change. The bitch is naked, shows her little hair in her pussy, puts her whole ass to hallucinate with him and in a moment he drinks it from her hand and with a crazy desire to start fucking her.