Kirith stayed close at hand, whispering into Kara's ear to suck her brother's shaft for him while she kept her own sex and anus in the air for the demoness to play with at her leisure.  "Take him as deep as you can go my pet, and do not worry about hurting him.  Draw blood if you want, and take the drug that is in his system to enhance your own pleasures."  Jacob nodded, making sure his blood was the aphrodisiac mix rather than the poison that he normally kept before nodding to his sister to go on.  "While you take him, use your tongue and cover every last inch of his shaft.  Do you understand?"