Either this half-sister is a slut or it's not the first time she's fucked her brother. Look how calmly she reacts to his appearance. And even though his dick isn't the healthiest, he's always around and she sucks it with pleasure. And judging from the video, the girl likes to be licked there. She even shudders when his tongue touches her clit. Yes, and with his fingers he helps her catch up before he comes inside her. It's nice to live with such an available sister!
And I liked the fat temperamental mom! By the way, the son was born with a pretty decent-sized dick. He must have been very pedigree.