It is highly unlikely that he will get an oral yeast infection. Yeast is always in the environment, and in the mouth and the vagina. Sometimes oral sex can cause a change in the vaginal environment which causes the yeast to grow and cause symptoms of infection. This probably will not occur in his mouth. usually, your infection will respond to the treatment and you probably won't have this problem again. If it continues to recur, your doctor might want to check for a rare type of yeast infection, which sometimes he might need to be treated for as well. But this is extremely unusual and I wouldn't worry about it too much, unless this problem keeps on happening over and over again.