Leon was prepared to have Andrei react more violently, and he was ready to let go, especially if he felt the memories of Andrei's time trapped and locked in a small space for decades resurfacing in his mind through their bond. Leon's goal wasn't to traumatize Andrei further, but to assert his place. If Andrei wouldn't or couldn't work through the broken emotions he was feeling, then Leon would help him. He'd be the glue that pieced it together so he could see clearly. See that he was safe, sure, confident and capable of carrying them both through those gaps that Andrei didn't understand or was afraid to face. He was home and blood was binding.
So when Andrei surged up, Leon had a gauge on his sire's emotions, keyed in like picking up a strong radio frequency. Andrei wasn't fighting anymore and he wasn't trying to escape. Andrei kissed Leon and Leon kissed him back without hesitation. He let go of Andrei's pinned and twisted arm and turned him around, but he didn't give him an opening to bolt again. He caught Andrei's ripped shirt and pushed him down against the forest floor, holding him there as he sat astride him and resumed the kiss. This kiss wasn't the lazy feel-good post-feeding haze kind of kiss they'd shared after Andrei had bitten him. This kiss wasn't laced with the flavor of Leon's blood, but it did have the presence of Andrei's fangs. Leon explored with more intent this time, leaning over his sire, the two of them shielded by the underbrush they'd tumbled into.