How long after a stomach virus do you have to wait to KISS someone without infecting them?

The viruses that cause the stomach flu are present in vomit and feces. They are not supposed to be present in saliva (unless the person just vomited). Your boyfriend will probably still be producing viruses in his feces so he should make sure he washes his hands well after he goes to the bathroom. I don't think he will have viruses in his saliva so kissing is probably fine. However, there is no scientific research that actually tested for the presence of these viruses in saliva a week later. So, I can't make any promises. You are probably taking a small risk by going there this weekend. However, you will still have a really nice weekend with him. If you catch it, you probably won't get sick until Monday when you get home. This is a hard decision. Good luck and I hope you don't catch it. For more information, please visit this website.