That happened to me last month during my talk in WordCamp Alicante.

I went there with one of my sons (he's 3). In the middle of the talk, he stood up from his seat and came up on the stage to tell me that he had to pee. Hilarious. The audience was quite amused, some of them even tweeted a pic :)

Great talk by @joanboluda and his little helper on #membership sites at #WCAlicante2017 #WordPress pic.twitter.com/XMPPDCFXrp— Piccia Neri (@Piccia) March 4, 2017

No child care in that WordCamp, I finished my talk with my little assistant. XD