@partyrock I haven’t, nor have I ever caused someone to. But FYI, this [Very NSFW] Google SERPs list makes it clear shit happens. Lots of the sites covering it are aimed at extreme misogyny. They glorify guys who are hung like donkeys and treat women only a cut above Jack the Ripper. Not only do they deliberately cause the model to gag and vomit, they verbally and physically abuse her as well.
But there are also sites dedicated to those who like to do this, and who deem it an extreme of intimacy, sharing something that many would consider disgusting. There are lesbians who deliberately gag themselves and anoint one another with a Roman Shower, then revel in the slippery licentiousness of it all. I suppose the appeal is similar to that of scat and watersports games. I can understand how it can be hot fetish sex. With the right person, I’d give it a try. But I am capable of being seriously kinky.
BTW, be very careful about actually clicking any of the links in that Google SERP list. Porn sites are notorious for tracking cookies and malware. If you want to visit one, check it first in Web of Trust. There are plugins for Firefox and Chrome that show WOT ratings on each link on a SEPRs page. Anyone interested in visiting such links would be wise to install one of the plugins.