wow it sounds like my son! ha ha ha! both my son (age 2) and daughter (age 6) did that. well my son still does it. and yes sometimes he vomits. however it is just one more of thier discoveries i think. i used to work at a daycare center in the toddler room. and would say 8 out the 10 children did it. some were more intrested in it then others. this one little girl i had did it ALL day long!! it drove me NUTS, but a few weeks later she just stopped. i think they just like to discover the feeling. (that is what my doctor told me) to a toddler all feelings are NEW. no matter what they are. but yes it is nasty, but not to worry it too will pass.