Hello from JustAnswer.
There are several infections that can cause such symptoms. It is true that yeast/thrush is a possiblity, but since the fluconazole did not help, that would be less likely at this point.
The primary concern at this point would be a bacterial infection of the urethra, the tube that runs through the penis, or of the prostate.
Infections of the urethra, also called urethritis, can be due to certain sexually transmitted germs, such as chlamydia or gonorrhea, as well as various germs that are not sexually transmitted. Since you are not having a discharge, a gonorrhea infection would be unlikely, but chlamydia can cause an infection with little or no discharge. Obviously, your sexual history would also affect the risk for sexually transmitted germs.
There are a variety of germs that can infect the prostate, and since the infected prostate secretions will exit via the urethra, it can cause symptoms from urethral irritation. A prostate infection is fairly common in men, and would be the most likely infection in someone in a mutually monogamous relationship.
A true urine infection is actually quite rare in men, but can occur, and would be more of a concern if the above causes have been considered and excluded.
If I can provide any additional information, please let me know.