By then, Lucas' eyes were cold, so cold they looked about to give the apartment a taste of the south pole. And he didn't even bother to hide it because the old man had torn any possibility of pretense apart.
He was about to die, but he just couldn't go die in some dump somewhere, could he? And he had to f*ck him before dying. Or before even being able to die, so he might have thought, 'why not f*ck the youngster to the end?', and decided to plan beyond just embracing death.
He really wanted to jump on the old man and tear him apart, doing everything to reduce him to pieces, ashes or even atoms. Unfortunately, he didn't know if he had some means to pose a threat or defend himself. And more than a fleeting satisfaction, he needed information to have a chance to bring his life back on track. So for now, he could only play along to get more of that information: