Hi, Hope You Can Help. I'm In A Long Distance

Hi, hope you can help. I'm in a long distance relationship and so really don't see my partner very often. For some time now he has said that a day or two after sex he gets itchy testicles but after a few days it does go away. The last time however, it was a worse than the other times. I have never had any issues, except the last time I thought I had a UTI but my sample showed to be clear, however it was diluted as I had been drinking lots of water. Any suggestions?
Thanks