[Tseng lets him struggle a moment. It's endearing to see Zack this way. Hot as well. He has to force his mind back to interrogation.]

Well you did say please. And you've been so good. Telling me what I need to know.

[He wants to encourage it. Reward it. He drops to his knees in front of him in one fluid motion. His lips close around Zack's cock a moment later and a moment after that the blowjob is well underway.]