Yeast Infections After Sex?

To preface, I have only had sex a few times with one partner however every time we do I get a pretty bad yeast infection. At first I thought he had gave me something so we went and got tested and it came back negative at this point I knew it was only a yeast infection. I thought this would be a one time thing but now every time we have sex I get one. Its annoying and neither of us know how to make it better. Has anyone else had this problem, if so any tips?