Bellybuttons, can you really break a seal?

So, I know that bellybuttons are a touchy topic.  Some people are grossed out by the mere word, "bellybutton", while it makes others giggle (I fall into that category) but for some, it simply creates unnecessary concern that the bellybutton is the only thing that keeps them standing upright. 

Take my husband, for example.  Although a cynical man, questioning everything, doesn't buy into the newest fads or conspiracy theories, is convinced that if someone pokes him too hard in his bellybutton, it will break his seal and therefore, he will deflate. 



Now, as a grown, logical woman, I find this concept to be ridiculous.  I mean, come on.  We all know that the bellybutton is simply what remains after the umbilical cord has been cut.  There is no magical inflator thingy that they use at the hospital to push air into you and then fill you up with air, like a balloon. (Although, I would imagine it would be really interesting if they did and filled the baby up with helium.) 

Where do people get this theory?  Do parents tell their kids this so that they won't play with their bellybuttons or put things in it, like marbles or brussel sprouts?  I think this mystery will elude me forever.