I'm Not Ready to be a Parent

My current role at my current client has me doing a lot of explaining, designing, some teaching, and coding. These things I don't mind. What I'm not prepared to do is be a parent. The last two days since I've come back from vacation, I've felt like a parent. Allow me to explain. One of the projects that I'm working on is headed by a female technical lead, where I'm doing a lot of the design work while she does a lot of the overall technical leadership. I have absolutely no problem with this as she's very skilled and easy to work for. However, one of our other team members (who is older than both her and I) is acting like a little child.

He had a relatively simple, yet very important assignment to complete. He was having issues understanding it, so he came to my cube asking for me to explain it to him. He acted like he had a blank slate. I explained it to him... several times. He came away probably understanding it. I later talked to my technical lead only to find out that he had earlier done the exact same thing to her. It was like a kid who asks mommy for something, doesn't like the answer, so he goes and asks daddy. And when he doesn't get the answer he likes, he acts spoiled. It's driving me insane. Does he think that the two of us don't talk to each other?

Now today he's had more issues and pulled the same stunt. The worst part is that I'm depending on him to complete his piece so that I can complete mine... so I'll end up being screwed by the deadline as he fitters away. I'd say that this kid is driving me crazy... but he's probably 15 years my senior. How he's survived this long I don't know. I want to ground him.