Mukuro bites Xue Yang's lower lip in retaliation for that thigh against him. His body practically weakens just by the contact and he growls against that mouth. Even he wanted to get free at this point he isn't sure he can given the position and so those pants continue to be a hindrance.

When he releases that lip, he smirks up at the other, "You mean you aren't already willing to do anything? I wonder if today is going to be the day you finally are."