He kisses his brother and then grabs his cock
A tent can be used for camping in the forest, pretending to be camping, or also having it in the house for when you need to go outdoors and never use it. But the use that this bitch gives it is very different from what the people who made it had in mind. Since she gets in there with her brother and after she kisses him, she grabs his cock. This one, being a man and human too, can’t do anything but grab her tits and then he has to fuck her. Even though she is her sister, it is something she cannot control and she knows it herself.