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!
While the blond was polishing his prick, he was actively threading her asshole - he did not leave her anus alone for a second, kept rubbing it, and checking its permeability with his finger. In the end he got what he wanted!