This is an important hygiene tip for guys using sex toys on girls, or for girls playing alone. Sex toys should never be inserted into the anus and then into the vagina without being properly cleaned. There are bacteria in the anus, which, if transported to the vagina, can lead to yeast and even urinary tract infections. If you're worried about killing the moment, a good tip is to use different condoms and/or different toys for vaginal and anal play. Never mix the two unwashed.