“Who wet my pants?” shouts mortified Reuben the bear when he realizes his friends are staring at the telling wet spot on his own pants. Reuben’s sham question became the title of a picture book by Bob Shea and Zachariah OHora, who talk about collaborating on Who Wet My Pants? (Little, Brown, Sept.), a tale of blame, empathy, and forgiveness.

What inspired you to tackle this universal childhood experience in a book?

B.S.: On a school visit, a literary specialist told me about a boy who had an accident in his pants. When she asked him if he’d pooped, he denied it repeatedly, insisting, “I really don’t know who it could have been—it’s a mystery.” I thought that this was such a hilarious lie in the face of an obvious fact, which inspired my story. But I made it about wetting rather than soiling one’s pants. This is not a potty book. Reuben’s accident is the catalyst, but the story is really about embarrassment and saving face—which his friends let him do. No one calls him out and says he has to come clean. I wanted to make the point that sometimes friends’ compassion is the saving grace.

How did Zach become involved?

B.S.: Zach and I met years ago through a mutual friend, Greg Pizzoli, and discovered we shared the same sense of humor. We talked about doing a book, thinking it would give us an excuse to spend time together. When I wrote this story, I thought of Zach right away. I didn’t want the book to be too flip, and I knew he would bring a sophistication to the story. His illustrations took it to a new level.

Z.O.: Earlier, Bob and I had tossed around some ideas that didn’t pan out, but seeing this manuscript, I said, “Oh yeah, this is the one”—even though it was a messy situation. When I started painting Reuben, I knew I would have done the whole book for free.

Any chance of a sequel or other future collaborations?

Z.O.: I would sign on the dotted line in a blink—whatever it takes to keep working with Bob. But in terms of a sequel—I have no interest in doing a book about number two.

B.S.: Definitely not an option. We’re going on tour for Who Wet My Pants? and I expect we’ll come up with some brilliant book ideas in hotel bars.

Today, noon–12:30 p.m. Bob Shea and Zachariah OHora will sign f&gs at Table 3.

Today, 1–2 p.m. Shea will be at the ABC/CBC Speed Dating Tea, in Rooms 1E07/1E08.